Stuck with sim card that cannot help me

My mtn number is suspended since February and no one did notify me. I called mtn because I couldn't buy data and airtime, they unlock that but locked all incoming calls and sms. I have been using this number over 10 years and mtn is taking my freedom away, i cannot login to any of the things need sms verification cz i don't receive sms and calls. This phone am using cannot work with mtn sim. So am stuck with their demo sim ***