I want nothing to do with Capitec anymore

I just wish I never had any business with capitec. i have a loan with them and for the month of November i had a financial difficulty so i called to arrange for a double debit in December and i even got an sms to confirm that. On the 11/12 they decide to debit my account of which i had no money as i told them and now my account is overdrawn. Who is going to pay for that minus? You know this year has been very tough a lot of people were affected due to the lockdown. I don't need unnecessary costs. We have families to feed with the little that we have but because to them its just business they don't care about their clients they just do as they please. They don't even have the decency to communicate with me to find out if i will get paid early this month or not just like other banks do. I am so heartbroken