Poor service from their customer service and complaints department

I fully paid off my accounts and they still ran the debit order. Now I been requesting them to refund me the funds and I all I get from their team leader is that the issue is under investigation. I have copied in the complaints department in my correspondence and well they have also been silent. This is the 3rd week where I have been calling in, sending countless emails with no resolution.

They are quick to sign you on and will give you all the attention until they have to deliver. I have fought with them countless times as they dont update balances and they dont request paid up letters. I have had to personally request paid up letters and send it to them for more that 2 accounts.