Wrong amount and debit date

So i signed up for data via Mweb if im not misten it was a day before or two days before month end. I asked the agent i=numerous times when will my debit order go off and if i would be charged for delivery fee. Surprisingly a week after i was debited and charged for delivery. my debit order bounced coz i didn't have money in my account. Again i had advised my debit order date to be the 26th they keep on debiting after the agreed date and am charged for a bounce debit order. Please contact me and fix your debit order date and amount.