Poor service

I can't believe it is so difficult to try and settle my Std Bank Vehicle Finance account. I understand that they are having a problem with their reference numbers but I would like to settle this account with them. When calling in, their call center staff , they say they don't know how to help as THEIR internet banking system will not accept the reference number that they have given me which differs from the first reference number, and say they are not allowed to put me through to a manager or give me her telephone number for her to assist with my problem. They finally got their manager to call me and she promised to call back the same day with a solution and that was a week ago ....nothing happened - What does one do??? I am begging and pleading just to pay them what I owe them and nobody will help me.