Mtn destroying there own clients

Good day MTN sales call centre keeps on harassing the company i work for support number asking every time if we want a contract while we have almost 40 sim in the field they phoned the support number 8 times just in the morning for the same thing and won`t stop it seems mtn does not want clients to be on there network if so I will be happy to comply might take a bit of time but i believe vodacom would be happy to assist. Phoned mtn call centre they can`t help I must send a email and no managers I can talk to so thank you mtn destroy your clients let see where you would end up