very bad customer experience

On Air sold me my new dstv explorer decoder, on completion of my details and debit order set up I told them numerous times that my pay date is the 27th of every month. on 27/08/2014 I was debited on the 25th and that caused an fail debit and Bank charges of R110, I was phoned probably about 20 times and got told that my pay date will be sorted out and debits will run on the 27th and that I will be refunded the R110 bank charge for the failed debit. 1 year later on the 26th of AUGUST 2015 I was debited early again and yet another failed debit and bank charges to me for R110. I have spoken to a lot of people even supervisors but nothing ever happens and I still get debited on the 25th or 26th and not on my pay date the 27th