Bad service and no one want to listen to me

I have problem with edgars I have 6 months account with them with no interest. From November when I receive my statement they was interest on my account. I call them and they explain to me that is error from their side it will be fixed by December.

Come December statement still the same. I called but is like no one what to fix it. They collection department is calling and send me emails.

I went to the shop I don't receive any help. Please assist me