The bank is ripping me off

I have been experiencing problems with the bank account regarding to the debit orders. My service provider has on numerous occasions couldn't debit my account and the bank has been taking the amount of R102 as a penalty charge fee. Sometimes it's refunded but sometimes its not. When I query it, I am told that I didn't have sufficient funds in my account. On the 3rd of this month a debit order was unsuccessful. I contacted the bank telephonically today earlier, on the 5th November 2024, to query the matter. The call center agent informed me that my account balance had pending funds which caused the debit order to be declined. My account balance was positive and had sufficient funds. On the 3rd November, later in the afternoon, I was able to transfer funds from the same account to another account. Can someone make sense of this and make me understand what is really happened.