Account settlement

I recently settled my account with MBD using the credit card link that had been provided. After doing that I called to try and notify them but had no success. On the 25th the debit order still went through making the total amount paid more than what was owed. When i called to enquire about this last week, I was put on at least 3 different consultant and told that I needed to email queries@mbd. I told them that I had done that already and had not received a response but the person i spoke to told me that they are busy and that it probably why they have not responded. Its been over a week and I still haven't 1) Received settlement letter 2) acknowledgement of any of my payments which is frustrating.