Repeat Debits on an empty account

Hi Cell C Team, I hope you are able to assist me with this situation, the past 4 months i have been unemployed. But I do get some money for survival. my issue iss my bank account has no money most of the time. I owe Cell R660 monthly however, CellC attempts to debits my empty account like 10times a month leading to Bank Charges of upto R2000 a month. as a result i am not able to even use my account anymore. any cent i get goes to charges that Cell C deliberately cause me. this contract was coming to and end soon but the damage on my account is just too much for me to not complain. is there a way you can help me fix this mess please.