Mtn won't unblacklist recovered device

A few months ago i was in contact with the mtn call centre enquiring about unblacklisting a recovered device. I was advised that i needed to fax an affidavit accompanied by a copy of my id doc. I've faxed the required documents three times already and my device remains blacklisted and no one cares to call me back on the number provided on the affidavit. I've been a loyal, paying customer to mtn for over two years now and this is how they thank me. I cannot go through to the contract call centre again as i've recently migrated that number to prepaid. I'm not sure what's expected of me anymore. Or should i remain with a blacklisted phone that i paid for in full and didn't blacklist because i was trying to be funny or if mtn expects me to back for another contract regardless of the treatment they're currently giving me.