R70 failed debit order

I have a contract for the past 7 years I have been a customer. For the month of September I got debited early and got charge for a failed debit order with an amount of R70. I called their customer care the agent yold me I have to pay it, how so when it hot debited 3 days earlier. I asked to give me her team leader as I was not happy with her pasdive response.sent several emails.No one is willing to rectify my bill amount. Why must I get charged for a failed debit order when my pay date is the 25th( Usually it debited the following day not day before especially if its a holiday. Usually I get sent an sms with options to choose from to say I will have money or not) Im extremely upset about this, In Cyrils economy I can’t pay R70 for the fun of it. I asked for a contract stipulating the above. Still no communication what so ever. After my contract is done definetly parting ways with Cell C and their ********** service.