Disgusting service

I have a mobile data sim deal with telkom & only when I reach work, there is no network, been trying to get this resolved with telkom for 3 weeks no success, when asked to speak with a manager, no manager available, promised call backs, no ond called me back, they log cases & the turn around time for some to pick up the case is 72 hours, over two weeks and no one has gotten back to Me