Pls assist me before is too late.

Goodday I received a call from DC expect on Wednesday explaining how they can reduce my debt they already have my personal details and don't know where they find it.They said they can reduce my debt for one installment of 5300 per month.The guy Rehgan send me papers to complete I said to him am not interested on Friday I received a message from home choice said they confirm that my debit order has been cancelled as per your request I call dc expert to speak to Rehgan they said he's busy with the client then the manager will call me in 2 minutes I spoke to the Lady she said to me u join and there's nothing that u can do. Today am from Truworths they said my account is blocked,PLS help me before they debit my money Or can I change my bank details