Breach of Contract and Swapping of my number

My Number is being used by an MTN user, so I receive their calls and messages, and they receive my calls and messages. I signed a contract and have had the same number for 10 years, and now 8ta and MTN have crossed lines and I don't have sole use of my number, as is stipulated in my contract.... The MTN user uses my data and airtime finished by the 2nd of each month, while I pay monthly and get no data or service...<br> <br> The 8ta service is also terrible, as I lose reception wherever I go!!!