Unknown charges

Unpaid item charges????? Let me start by saying " FNB is charging us fees for items we don't know about, please go through your bank statement"

Ok.. so let me explain... on the 18 march 2025 i bought items from the debit account while I still had funds in but I get a charge of R180 and R90 for 3 items FNB paid for when I had no funds therefore the account when in negative., the money gets debited from my account (meaning the money is gone, FNB has reserved that amount and my balance has gone down....) (However FNB have taken the amount from my account on the 17th). I query this someone tells when they are away if this and will refund the funds and later some to tell me they are charges. My question to this is why charge me an unpaid item charge when you have already deducted the amount from my account. and this month's is is exactly the same. Last month about R700 went in this so called charges and this month same time they have started to charge me the same. R270 and R180 so far and they are saying they are charges for items unpaid for which is impossible for I do not have overdraft facility of any kind. Why were funds deducted on the day of purchase but later considered unpaid items. What could cause items be unpaid when there are funds at the time of purchase. Now I see that in 2017 an individual had the same issue with me and FNB upto seem not to know what's happening too. This is not right.