Amazon - INCORRECT REFUND AMOUNT

Hello first of all i want to inform you that i am not feeling that much proud to be a Amazon prime customer because Amazon has not treated my ever as a prime customer who needs better service Better inform but Amazon has shown it failure to do such things. And allow me to say about my journey with Amazon for an order iqoo z* mentioned above.
So for that i want to inform you that on *th dec **** i ordered a mobile phone amounting rs **,***.And for that i exchanged my old device oppo f** whose exchange value was rs**** (Rs **** phone's value+rs**** exchange bonus).And by exchanging that device i paid the rest rs**,*** by using my Amazon pay balance.And after that it was delivered successfully on *th December ****.So after receiving that product i identified some problems like vibration issue and dent issues in that device so that i informe the same things with images to your customer executives. After that there was an inspection requested raised for this.But on the *st inspection day the technician without visiting my address and verifying my device physically he told me to go to service centre for bringing a letter where there will be mentioning of such issues by iqoo service centre.But while visiting iqoo service centre they denied me to give any such letter.So they suggested to submit that device so that they can repair the device.So the same thing i informed to the technician that they are saying like this so after that the technician denied me to submit my device in the service centre because my phone was in return policy by Amazon.So i didn't submit.After that he told that i ll arrange a replacement so i trusted his words but after inspection service order closure there was no replacement so again i contacted the customer service centre and informed all these things.So after that another inspection service was arranged so at that inspection the technician verified my issues and updated thr same in the note.So after that instructed me to contact customer care for replacement and refund on **th December so after that the customer executive arranged a replacement but one issue was there because of no stock it was showing a longer date so that the customer service executive asked me that though a longer date is showing you can cancel the replacement and you can take refund.So i tool some time to confirm her about my decision.But after checking all things i chose replacement and the replacement product was shipped and to be delivered on Wednesday.And i have my plane ticket in the same day at *.**am i can't accept that replacement product so on **th December i informed this to your customer executive so that he created a refund request where he mentioned that i will get ***** as i have paid and **** my phone's exchange price i.e rs**,*** will be the total refund amount.And after putting the refund request a mail was there from Amazon with a mentioning that RS **,*** will be credited to my original payment mode.and on **th December **** at *.** pm before initiating refund another mail was received that refund of rs.**,*** has Been initiated but while checking my Amazon pay balance Rs ***** was credited to my account instead of **,***.And while reporting this issue to the customer executive he replied that the additional exchange bonus amount rs.**** can't be refunded.So i want to inform you that from creating return till issuing refund there is no mentioning about the non payment of exchange bonus neither by in mail nor by in telephonic call.So after refunding the deducted amount your executive arr saying this.So i want to inform you that your executives all well experienced about the company policy so was it not their duty inform such thing that the exchange bonus amount will not be refund so that i would not have created return request for this because if i will do this i will suffer a heavy loss.And after doing return i am being Bounded to bow my head in front of you because i have handed over my device to you so everything has gone to your control so that you can check for ordering same product again I have to pay extra *** rs on Amazon. Was it fair? Was it good customer service to a prime member.So if you can't respect a customer in a well manner at least don't disrespect them by imposing a heavy loss burden on customer.So from this issue i have sacrificed several things like a working day to go to service centre and daily calling to you executive what i get at last rs**** loss because of yours executive's mistake by not informing me about this deduction otherwise i wouldn't have cancelled my replacement product.So as a customer i demanded to get justice but I didn't get which is very dissatisfying. Amazon is such a big company which is putting a customer to suffer loss instead of doing any profit.
So sorry for this long message because for me **** rs is a big amount because i belongs to a middle class family and since *.**pm i am very disappointed with myself so when i couldn't control my emotions i wrote these things before you.Then all yours ..I am attaching few screenshots below for your reference where any of your executives has mentioned about the deduction of exchange bonus.So do whatever you can for me... because this loss is not a small loss for me...