MTNSP DOES NOT WANT TO TERMINATE MY CONTRACT!!!

On the 16th of March I sent an email to MTN Customer [Email Removed] alerting them that on the expiry date of my contract which is the 4th of May I do not wish to have the contract renewed because I am not happy with their network coverage in the area where I live. I received an email from Araf Mohammed (MTN Retentions) confirming that my contract would be terminated on the 4th of May and I would have to call their 808 number either on the 4th or on the 5th of May to have my number migrated to prepaid. They have not terminated the contract and I have been trying to call 808 since yesterday with no luck of getting through to an operator, I have even tried to contact them via Twitter and sending emails but I have not been assisted. The same thing happened last year when I tried to terminate my other contract and I ended up being billed for a contract I was no longer using.