Incoming calls blocked with no communication

I have been an MTN customer for over 15 years. Today I could not receive any incoming calls. MTN never even bothered to send me a message or anything. People tried to contact me I had to return calls who is going to compensate for these calls MTN? Further more my kids school called me and surprise surprise they could not get through. If they was an emergency I would have sued MTN for this. What happened today was totally unacceptable. I demand answers from the manager as to whom compensates me for today.