Fnb not cancelled my policy

I opened a fnb life accident policy in July..a view days after i opened the policy,i cancelled it coz i heard im not going to be wrking due to the covid..bow that i want to use the account again i discovered that the account is in neg 800r..i phoned in and ask why my account is in such big arrears.I was told its service fees and unpaid debit fees of the accident policy.. I told the consultant i canceled it long time why do you accumulate charges on my account..i spoke witj +-15 ppl today.. How can i be held accountable for charges but the policy was cancelled way before it was even started. Am very unhappy..im going to get a little bit of money friday but fnb will deduct it again due to accumulated charges.How can fnb do this since the policy was cancelled and the fact that we also struggle during this covid...i ddnt had Money for a long time now fnb will take the little bit away from me and my family.Charges i can be held accountable for. This is so not fair...what must i do..i need help..im not gonna leave this thing..me n my family were hungry for long time now fnb wana take away a little bit from us for charges accumulated which is not my problem...am very very unhappy...