Airtel Broadband - Serious commitment issues

Hey, my name is Mudit I am from Chennai. So I have been using Airtel broadband since the past * years (broadband number - ***********) and I had registered a complaint against them for commitment issues on **th of May because they had changed my plan Fromm *** INR plan to *** INR plan on January ** **** without my consent and when I got to know about it on April *rd I called Airtel customer care and spoke to them about it and one superior (mr.bhaskar) accepted that it's their fault and he gave me the credit for all the excess amount paid but some of their executives before that told me that it was never changed and all that so I received false information also from their end and since then I have asked them to give me a additional benefit for the trouble caused and never received any response, I tried mailing the nodal office * times and they never responded , I call customer care for anything they just place me on hold and hang up on me after ** mins i have wasted so much time and energy on Airtel and now it's also affecting my mental health because I lose my temper more often because of this issue it's been a very irritating problem for me.