Customer for more then 18 years!!

I have been a customer of MTN for more than 18 years with the same number. About a year ago i took out another contract (WIFI) with MTN.

MTN notified me about 2 months ago that i am due for an upgrade but did not wanted to upgrade at that time. The contract was running on a month to month for the sim card and still paid it as i did not want to close my account. Yesterday i went in store to do an upgrade and the store told me that it has been declined. He was not able to tell me why. I phone the customers call centre and they advised they don't know why. NOBODY is able to tell me why. I am paying more on my account every month as what i am suppose to pay for more than 18 years!!! I have sent mails waiting for answers but no one gets back to me

If this is the way for treating a loyal customer i will not recommend them to anyone and they can take and cancel all my contracts!!

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