Jet account

I have made a payment in August . I also called mbd to check if I still have amount due , I was told I still have to pay the remaining amount but is the last payment , I arranged a debit order it went through and I was told i will be provided with settlement letter. I have been trying to call their call center for a month no one answer I have send email as well no respond . When I check my credit report it's still shows that I owe the same balance I paid .its so difficult to get hold of mbd.