Account in arrears due to late banking

I noticed some strange activity in my account sometime in December on the 23rd. I transferred around R500 into the account and in the morning there was a balance of R3000.

I'm not aware where the money was coming from and now I noticed my account is on a -R3000 and I do not have an overdraft. I believe i spoke to their service specialisy earlier in the year regarding this.

She explained to me but this still does not make sense, I do not have any debt orders on this account that could have possibly bounced resulting in my account in arrears.

I cannot be held liable for the system banking late and deducting funds later on. There were funds in my account and naturally I used them for my December expenses. I do not have an overdraft on this account therefore I couldn't have possibly used funds i didn't have, my account should not be on a negative balance when I didn't use the banks money.

I cannot be held liable for this unfortunately