Horrible customer service

I opened my Vox Account last year. I have never missed or skipped a payment eversince; even the very first deduction that you guys had made of R824.60, I never disputed it (although it was questionable as the contract never mentioned any extra deductions). February this year I called your helpdesk indicating that I wanted to move my debit order to a different bank account as I had switched my salary to the new bank account. (I never got thorough assistance; instead I was told about a portal that I don't even know). I had to transfer money from my new account to the old one for the debit order to go through for March. I made another transfer for the debit order at the beginning of April so that the debit order can go through again. Now at the beginning of May when the debit order went through on my previous bank account, there was not enough money in the account. I scheduled the payment on my new account and it was set to go off on the 5th of May. At that time I had already received an invoice that showed the R435 that was due and interest of R35. On the 5th the payment went through, and then I got an email saying my account would be suspended because it was in arrears with R506 (I don't even know where that amount is coming from as my account was up to date throughout). Kindly explain where the extra charges are coming from (except the R35 interest that I fully understand). My wifi at home seems to even be suspended whereas I paid. Your assistance in resolving this issue would be highly appreciated as it is hampering with my studies and my service delivery to my clients.