Dstv Disconnection

My account was disconnected this morning the 16/12/15. I always pay my account on the 15th on every month or on the 16th should I be late. On 12/12/15 I received an SMS say I should pay on 14/12/15. I didn't pay attention to it because I thought twas a system error as during festive seasons networks get overloaded plus on the contract I signed with them it's clear that I pay on the 15th of every month. I called them today the 16/12/15 and I couldn't talk to the operator because I demand to know who changed my date on the contract from 15 to 14. Thank you