Cell C N1 City -unreachable

I have tried for 2 days to get hold of someone in store, but the ***) number rings and goes straight to voicemail. How can a store have one cell phone ( if this is the case as there is only one contact number) and then have the unit either engaged or just switched off. I am a cell C client for over 10 years and this is ********** . I will rather take my business elsewhere if it is not wanted by Cell C.