Standard Bank Benefits from keeping quiet

Standard Bank are unable to assist telephonically or in the branch, just get told to wait for this and that. I gave Standard Bank consent 8 years and 4 months ago to increase a debit order on a loan, that would of meant the account would of been paid up 3 years ago but they never did that and I had no reason to contact standard bank because a debit order kept going off each month, no I find out the account is overdrawn although paid for 8 years and 4 months, further more never have they contacted me even though the account should have been settled in late 2017. My responsibility was to ensure my debit order goes off, there responsibility was to increase the instalment, but even after all this the account shows on my credit report as paid correctly.