Please help with this ********** case from MTN and Pinnacle.

This compay gave me a phone and now it's blacklisted. Phone was blacklisted by Huge Connect because of ********** purchases. I had nothing to do with this, I'm a customer and I don't even know where and how they get their phones. Now no one can assist me. Mtn said i must contact the insurance company and when i contact this company they say they can't Assist me because they are no longer pinnacle mobile insurance. I'm stuck here with a phone that I paid for but its black listed. Please help me