Paying for R479 unlimited 24/7 option but placed on R250 unlimited offpeak

My simcard no longer wants to connect to the internet in the evening or at night. During the day everything is fine but at evening I can't even go to WhatsApp. My router shows that it is connected, the bars are there and the light is blue. I even put the simcard on my phone and it says "no service, emergency calls only" but during the day every thing is fine. I feel as though I am placed on R250 option whereas I am paying for the R479 unlimited 24/7 option. Please will you look into this, fix and refund me because even my profile says my off peak data used is R0 which means you have placed me on the offpeak option.