Pathetic Service from Cell C Retentions

I have been waiting for over a month to have my new contract upgraded by Cell C after the ran a promotion, where you get a new LTE Router, 20 GIG Anytime and 20 GIG Night Data. Each time I call Cell C, retentions department they promise to call back but nver do and their Supervisors don''t want to come to the phone for an escalation. They have provided a really ****ty, pathetic service to me.