bad service

Everytime my walka stops working and shows a E19 or E16 error code even though my account is up to date. To think that I upgraded to the dstv explora a couple of weeks ago. Last night the same happened and I'm still with the problem now at 21-30 even though the call centre said it is active and they will clear the error. I have to use a lot of airtime and time lost and you don't get reimbursed. I am ****ed off because I am at work and can't watch my programs. Please get competent people that can deal with our problems. What am I to do now as my damn airtime has been used up trying to fix your mistake. This is not the first time and I bet not the last