Breach of contract

I took out my contract with Nashua and signed my agreement with them 2 years ago. I had the same contract for the past 2 years, it had a limited locked to it. When my calls reached R100.00 the phone will soft lock, and it will not allow outgoing calls and internet access, I cloud only get incoming calls. <br> When autopage took over my contract this was override the limit arragement without my knowledge and my expected to pay for all my call that i made as the line was never soft lock. IS THIS MY PROBLEM, CAN SOMEONE SORT OUT THIS, AS IM NOT PREPARED TO PAY FOR SOME I DON'T HAVE KNOWLEDGE OF. <br>