Kotak Mahindra Bank — No response for pre closure request and changing personal information without my consent

Address:

Mumbai City, Maharashtra, 400067

I applied for a personal loan, after six months i wanted to close the loan, when i was informed the term has changed to 1 year lock in period. No intimation sent to me.
After 1 year i did contact to get pre closure quote and was advised to write to service. [protected]@kotak.com.
I did write to them along with the previous discussion. There was no response, hence i did call the customer service desk, when i was surprised to lean that my email address was changed.
I was informed to visit a branch and submit change of details form, to receive a response.
When i did question as to why my personal details were changed, there was no answer.
I requested for a supervisor, as usual they were busy and a call back was arranged with 48 hours, which i havent yet received even after 10 days.
I received a call from closure team to verify if a request was sent by me, when again i was informed about a 3rd email id belonging to an unknown person registered on my account.
I have not yet received any response nor a resolution.
Now as i cancelled my ecs they are charging me unwanted fees and threatening to report as a defaulter.
I need this resolved as it has cause me monetary and mental torture.