Ismail and Wesbank on bad service

My mother passed away on 2017 and had car finance with Wesbank, after her passing her account was taken to Ismail and Dahya and the account had a balance of R130 000. To date i have made payments of R 113 000 and instead of having a balance of R 17 000 i have a balance of R 30 000 and on their statment it appears as balance adjustment of R 13 000, this was appearant after i made a cash transfer of R 100 000. I have emailed and called regarding this balance adjustment and all i get is that an agent will be in contact, its been months now and no one has came forward to explain what is going on there, i wanted to settle the account but because of this thieving behaviour i am not going to pay any cent until this issue is resolved, they can take me to wherever they want for all i care, Wesbank really needs to take account of these many complaints regarding Ismail and Dhya and their *********** stuff