Rewards Registration

Hi<br> <br> I was previously registered for the rewards programme.<br> For the last month or so i am unable to logon on my cellphone, message is that my number has not been registered. I have not changed my details and i was previously using this service.<br> <br> I am struggling to get help as apparantly everything looks in order on their side but i am still unable to login.<br> <br> Please assist<br> <br> regards