MTN refusing to credit me as per agreement

<p>I received the below email from retentions when requested to upgrade early after a telephonic discussion we had agreed to the below, now that i upgraded on 02-05-2016 i have emailed this lady and customer care and retentions department but MTN are ignoring my emails for 3 weeks, it was agreed and documented that i am entitled to 3 months credit and as a customer of MTN for the past 6-7 years i surely hope to receive my 3 month credit!!</p> <p>Good day Mr Verster,</p> <p>Thank you for you email.</p> <p>As per our telephone conversation, I did not approve the premature upgrade on the cell number *** however approved a 3 months FREE subscription when you renew the contract anytime from 1st May 2016.</p> <p>Kindly email me directly once the upgrade it's captured : ***</p> <p>Trust the above it's in order.</p> <p>Best regards,<br /> Wenzi Sibanyoni <br /> MTN Retentions</p> <p>Reference Number: ***6"</p>