Mamaearth - cheating and harrasment

Hello Sir,
I signed up on Mamaearth with referral code in which Mamaearth gave *** Rs. added Signup offer to mama wallet. Then their offer was going on Buy One Get One with code OMG. I added some products to my cart to order and applied this offer. After applying the coupon, I saw on page that the option of add gift card was highlighted. Then I purchase Rs ***/- Mama earth gift card from my Paytm. And as soon as I added that Mama earth gift card to their app, the buy one get one coupon offer got removed. Then I called their customer care and spoke to Miss Sapna. Then I told Sapna that I was ordering the product from your app, so my gift card was not working with the coupon. Then she said coupon and gift card don't work together. Then I asked why your gift card option was not disabled when I applied for the coupon. If it doesn't work with coupon.Then Sapna disconnected the phone saying that your voice was not coming whereas I was hearing his voice. I also have its recording. I felt that Miss Sapna was not able to understand my concern, so Miss Sapna disconnected the phone by saying not audible. then I called again to customer care.
Then I talked to Miss Kanishka. Miss Kanishka understood my concern well and promised to help me. Then she told me place a new order then cancel the order and call her again to talk to her if the call was connected to another representative. As soon as I called again the call was connected to Miss Diksha. She refused to transfer the call to Kanishka. And disconnected the phone without listening to me. After that I called customer care *-* times. After running for some time the phone got disconnected *-* times without connecting Mamaearth. Then I saw your website on the net. To complain against Mama earth. Main concern It's not about gift card of rs. ***/- it's about cheating and harassment. When mamaearth gift card and coupon combination was not supposed to work then why didn't Mama earth disable the gift card option on the payment page. I wasted * hours in calling customer care and there was no solution.. I have all the call recordings. I am filing a case of cheating and harassment against them. Solve my problem as soon as possible.

Regards.