Cell C not helpfull

I am fed up with Cell C and the inferior stock they supply to me. I have a wi-fi router and since I got it 11 months ago I had to replace the simcard 4 times already. Today I went to the Cell C shop at Westgate Mall in Mitchells plain where I was told because I did the previous replacement at Somerset Mall they could not do the refund for the simcard because the stores was owned by different owners. I was told I had to go to the store at the Promenade because that was owned by the same person as Somerset Mall branch. Apon my arrival I was told that they could not do the replacement without my ID. (which is **** because i never needed to provide it for a replacement) I pay alot of money every month for my cellphone and internet so I would have thought that I was a client of Cell C and not a specific store. That being said that if it was possible i would cut all ties with Cell C and move to another provider as soon as i get the chance. Big kahunas of Cell C please sharpen up your stores private owned or not I am really tired of being messed around. Looking forward to hearing from you and hearing what solution you have for me.