Refund and paid letter

I have closed All loans with Finchoice and now there were funds credited accidentally in their account which wasn't meant for them from my debt counsellor and now getting a refund has taken me 2weeks to fight for my money back, even escalated to management but nothing has been done, this is pathetic, I would never ever Suggest them to anyone, even now I am still fighting to get my refund back, I am very livid and not willing to let go because my credit money is sitting in a closed and paid up account which I keep sending proof of payment for and I keep getting excuses that they haven't received anything and I have sent a number of emails , even to their manager but still no progress, I want my money back period...and also get a paid up letter as proof that the loan is officially closed.... *********** call centre agents who keep giving different information all the time... it's ridiculous