Poor Service

I have made payment by mistake at HomeChoice instead of Home Loan, been calling for assistance to get a refund. Customer service told me the account is handed over to nimble they can't do anything from their side. I called Nimble and I was told the money is not reflecting yet to them and it will take about a month. I wrote an email to ***, no feedback or a call, been calling having a back and forth interaction with different people and no one was helping. Still this is not resolved and my question is how my account endup to R11 000.00 while they sent me statement my balance is less than R2000.00 and I have received Paid up Letter from them a years back. I am so disappointed with their service.