Double deduction with out notifying me that's bad

I change my debit date from 20 to 25 starting in March 2015 and yes in March 2015 they did debit as we agreed on but now in April 2015 they said they didn't get money in my account and i ask them how because I'm getting paid on 25 every month now and on March they did get money .My problem with them they did sent anything notification no phone calls nothing and I'm asking them why they didn't disconnect the DSTV now they said sometime when you paying via debit order the systems don't disconnect i watch my tv for the hole month knowing i paid my DSTV now in May they debit R638 which take me out of my budget for the month I'm asking why they say the i didn't pay DSTV for April .Why they dint send me massage on my tv as they use to because when i update my details in Feb 2015 i confirm my number but even now they still have the old number its only now they change of which I'm even sure if they really change it .So i want my R319 back i can't be panellise for something that i was no aware off last week i spoke with Nkqubela about this he ask me to go to the bank and ask for bank statement and send to the as proof that there was money in my account of which i did i sent to them but i