Standard bank making changes to contract without any permission given!!!

I took out a vehicle finance plan with standard bank 3 years ago. All was good until a week and a half ago i received a statement saying that i owe them double the amount of my monthly payment keeping in mind that my payments have been paid on time and is up to date. When i phoned them on the 18th of May 2020 to enquire what this is for and why i need to pay this i was told it was for a holiday payment that i have NOT APPROVED TO GO AHEAD WITH!!! I was told that the enquire is escalated and that they will phone me once it has been resolved on the 19 may i received an sms saying it has been resolved and will received a call. I waited for the call till 21 May 2020 keeping in mind i have NOT RECEIVED ANY CALL!!! i phoned them again and was told that the person ( Toney Mabasa) has tried phoning me on the 19 May yet i haven't recieved a call and he made a note on the system that when i phone again i need to be put through to him as i was at work i asked the lady assisting me to please get him to phone me back she was kind and helpful enough to sent him an email an cc me in the email asking him to phone me back which 5 days later still haven't phoned me back or responded to any email!!! I just want my account to be reverted back to how it should be. Funny enough when i asked who gave them permission to go ahead with a payment holiday i was told BECAUSE I AM A GOOD PAYING CUSTOMER THE SYSTEM GRANTED ME A PAYMENT HOLIDAY IMMEDIATELY WITHOUT ANY PERMISSION!!! Till this day the problem is still not solved and i need to keep on spending money to follow up on them to sort out the problem they have caused me!!!