Pre-payment penalty on cc account

Dear Sirs, I have been banking with Axis bank for last several bank and using CC limit. I was compelled to move out to another bank at the time of renewal due to following reasons : -their services are pathetic. i am tired of chasing them again and again for every little thing. It has disturbed my routine business many times. -i have writen to their nodal office several emails in last few months but they dont care to intervene or reply -they have overcharged me on many occasions the forex margin which they had promised me at the time of last renewal. But now they are refusing to agree they had ever committed that margin. Due to covid last year, the officer in charge of my renewal (2020), was not attending bank everyday and had promised to send me a mail confirming the margin but they didnt. I found out later that they have been over charging me and now they are asking me for a proof which i cant produce. -their interest rates have been high every year compared to other banks but being a small company i continued with them -i am leaving the bank purely due to lapse in their services which also their SME in charge manager knows. -i have sent them several emails in last few months warning them that i am being compelled to move out because of lapse of services from their end. now when i have moved my CC limit to another bank, they are holding my property documents and asking me to pay pre-payment charges Please let me know how should i fight "pre-payment penalty" with my bank. Anish