Absolutely ridiculous service and no logical answers to my questions.

I have vehicle finance account with absa.completion date January 2026.my instalment is R2400 per month and in January 2025 I paid in an amount of R23675.thats about 11 instalments in advance.i am continuously getting emails and calls telling me that I'm in arrears with my payment.How is this possible.How ridiculous is this.I asked them to talk to my husband as he handles this account.They refused.i sent them a letter of Power of attorney.Their response was that my husband and I need to go to a branch and sort it out.I live in Cape town,my husband lives in Durban.Thia is the worst service ever and I will not recommend Absa to anyone.