Ill service

I have a contract with Telekom they debited their money every last day of the month with out a fail so last month i was reversing money from my bank that i did not authorize i made a mistake and reversed telkom and that was th biggest mistake of my life i made??? i tried to call them because they dont communicate they told me my account has been handed for collections and the collection department started debitinh money from my bank anytime they feel like and the was no money in my account their debits cost me R450 from my bank i am so made of Telkom i dont want anything to do with them they dont communicate they do what ever they feel is right for them not considering their customers ?