Credit Balance: Collection

Account with a credit balance handed over for collection. After trying on several occasions to change my banking details I missed a debit order. When I realised this I made an immediate EFT payment. A few days later my old account was debited as now there was some funds in it. When I finally did manage to change my banking details the same week my new bank account was also debited on the 14th June. At this point I had already made three payments totalling more than R1300.00 on an account of R505.00. A few days ago I'm getting emails from NuDebt threatening to take legal action on my account which according to them is in arrears. Please check your books and inform your hound dogs to step back or risk getting reported to NCR. While you are at it. Issue me with a refund.