MTN is useless when it comes to communicating with customers.

I have been in and out of the country, I would be out of the continent for 2 to 3 months. When I tried to use my mtn mobile number, a "Not registered on network" was on my screen on each an every time I tried to use my number. I went to Hemmingways mall in East London to seek for assistance, that was after I tried the 135 call centre number for the whole day, that number is useless. They couldn't and also they were puzzled. The cellphone number is still active but the number on the sim card itself is deactivated. To me it meant that the number has not been taken yet. A request was sent but still nothing is happening. I am using the same mobile number for my WhatsApp, for work communication, the same number I've got an ewallet money on and without my cellphone number my money is gone. Why is mtn not communicating with customers when they are about to close/ take away the number? Why is mtn not informing customers that there is an option that can be taken when going abroad? I only found out about some "rules" when I went to their branch. MTN is failing us big time, all they are good at is to bombard us with adverti*****ts, and lots of unnecessary nonsense to the information we need to understand how the products we have work. I have been a loyal customer for quite a while, with two sim cards.But its okay they can take the number and give it to someone else with my ewallet money included.