No caller ID on contract SIM

I've taken out a contract two weeks ago at the cellphone department in Edgars, Tygervalley. On the contract that I've signed, it states that I am being charged an additional R10 every month to see who is phoning me, to which I agreed (what choice do contract customers have?). But since the contract SIM was activated, I have not been able to see the numbers of a single person phoning me, even though their caller ID is set to \show". Yet I am being charged for this service. I would very much like to see who is phoning me."""