breach of contract

I notice at the beginning of this month that my benefits are differ than the previous months. I call cell c contact centre to query about it. I spoke with someone and she said my benefits for this month as is follows 150 minute, 150 sms and 150mb. I asked her why because I was receiving 450minutes, 450sms, and 150mb. she said there is nothing that says so on their system. she is going to escalate and I received the sms with this ref no. ********** 158. Later the same day I received a call from cell c someone offering my the data contract. I told him I am not interested because of the problem I experience with cell c. He told me I was getting the other minutes for free and cell c got a right to take it back. My question is why I was getting it for 23 months not so 24 months as per my contract. I am still gonna pay for my subscription and I was not getting it for free because I was paying.