Unfair charges

Fnb and the charges are ridiculous, i have a private Account and there were transactions on my account that took place while i had funds available and they were successful, on the 27 and 28th 2 debit orders went off my account and it brought my account to an overdraft, i immediately messaged Fnb on chat to let them know they must reverse those transactions as i cancelled the funeral covers because of the Covid 19 impact, instead of reversing the pushed the debit orders back and the Shopping transactions in front as if i bought food while my account had no funds. im now sitting on overdraft and im being charged 250 x 3 and 125 for funds not available instead of reversing the debit orders since they deducted while there were no funds my account should be in a lo balance. i cant keep doing this with this bank every month i want to deposit money in my account but it needs to be rectified again. n one helped me since the 28th of May i even did the Help me tag on Covid 19 to request the debit orders being reversed as it brought my account to overdraft. this happened 2 months ago and it was corrected and now its happening again. We are all going through financial drop at the moment and being charged for something that is not my fault by Fnb is really unfair.