Unauthorised access to HDFC account

This is in reference to my credit card no ************2724. I opened the account some 9 months ago and due to some financial difficulties the card went overdue and I started incurring heavy interest charges but I still managed to pay a partial amount as demanded by bank. In the last month I requested the bank to refund some interest amount as the charges I paid were enormous and the purchases were made for just 000. The bank people said they will refund the interest if I paid some amount of it , I DID the same and when I called sometime later they refused to honour my request and started calling for payments again some 10 days ago , I said I wil not pay unless they fulfill thier promise of refunding some amount of interest . They refused to do that saying I wil have to pay again some amount if the interest has to be refunded . I had no money at that time so when the salary came into my account I tried to call the bank to claim the amount and refund some interest , but by that time they had blocked my card and gained unauthorised access to my salary account and putting all the funds on hold .Now whenever I call the manager he says he cannot do anything about it and refused to listen to me after listening to everything. I am living without any money now as the bank has put my funds on hold claiming they are going to deduct whole balance of credit card from it . I just wonder how the bank could access my account without my authorisation and why my credit card was blocked without any valid reason. Hope to get a solution from you soon!