Bad service

I took a loan last year in November from Direct Axis and settled my loan the previous month on the 25th. However, they are still debiting my account and are not willing to refund me the incorrect debit done to them. I fail to understand how they keep debiting my account because the paid amount had my account number (as identification on their end.) I've been calling to follow up and was advised that they haven't receive my emails. hence they are the ones who gave me that email used.