Mtn contract paid up but not updated

I have had an mtn contract phone which i eventually did not pay up for a couple of months because I became unemployed. Mtn sent Saya recoveries to recover the outstanding amount, I paid the amount in full for 3months. I am now permanently employed again and looking to purchase a vehicle but I cannot get finance because mtn refuses to update that I have paid up the outstanding money I owed. I have called multiple of times and emailed the paid up letter to over 4 people who do not respond to emails at all, this is really disturbing because I am in serious need of a vehicle. Mtn helpline is unprofessional and they always pretend to help when they clearly aren't, I have had some people give me wrong email addresses too.