Already worst, now beyond that..incredible

Cell C, I have sill not been able to cancel this contract, you are now still billing me and demanding money from me, your retentions department asked me to return the router to the closest Cell C provider, which i did, they don't know what to do with it, and you won't cancel it because of some number I should have received from the store I gave the router to (as i said they know nothing about such a number) sad to say this is the worst service ever in the history of my existence.