Debit order date stays on 25 causes bad name, debt

I requested to change my debit order date on the 20 May2015 i accept that it was after the 15th of the month and cant change it after the 15th. I only received a reply on the 26 June 2015 that is 36 days later so once again i cant change it via email because it passed the 15th, but in the meantime I UPGRADED like an idiot supporting MTN once more.On the day of me upgrading 9th June 2015 I changed my debit date on the system during the co**** of the month i went back to the store to make sure my debit date has change but it kept it on the 25th meaning my debit order bounced and I had to pay for the fines, as I understood my debit order did go off on or before 1st of June but on the 30 June i received a message which stated i must pay an X amount which was less than the original amount for that I thought it was all in order i asked the consultant if I must pay the full amount or smaller amount she said smaller now i cant phone out and i wont receive my monthly airtime and data.I think its unfair to me now im punished for a consultants mistake.My name is through the mud and my credit score this needs to be fixed or you will loose a client. I did not receive my prorate data since 9June