errors on account sbsa vehicle finance

i have taken vehicle finance from standard bank in June 2015. and from day one there was a issue with a deposit that I paid to the dealer and standard bank paid the wrong amount to the dealer(amount included the deposit) they then sent messages to me indicating that I have not kept my end of the contract by not paying the deposit into the vehicle account. I then called the dealership and asked them what the issue was and they then contacted sbsa vehicle finance and standard bank admitted that they made a mistake and gave them an account number to deposit the extra money, the dealership did so. but for a month after that I got messages that I was in arrears. I called many times and they told me they are working on it. until today I have not received and calls from sbsa as to what happened and how it was resolved. I then started getting messages and calls again stating that im in areas, I thought this was the same deposit story, but it was actually interest on the lost deposit that was now showing on my account. I called and sbsa said it was an error on their side and they will correct it. today again I receive a call regarding this. nobody at sbsa calls and explains anything.