Improperly advised when purchasing data bundles

On 27 March I purchased a 8ta Sim at Telkom's Mobile branch in Kenilworh Centre (Cape Town) and arranged instore for the 25GB + 25GB data bundle to be loaded. When I arrived home and tried to use the sim, I realized there's no coverage. I had to provide proof-of-address in order to RICA the sim, so the representative had my address and surely could've checked that my residential area had coverage and should've advised me accordingly? On 28 March, I contacted the call-centre and they advised me to go back to the shop from whence I bought the sim. Went to the shop the same day and they informed me that I should select the MTN Network as 8ta roams off MTN. Tried this when I got home immediately afterwards and it was thus either a blatant lie or complete incompetence. Called the call centre again and they suggested that I go back to the shop???? This after I told them the shop gave me ill advice in the first place and afterwards again ***********ly advised me!! Now, I'm told they have a 72 working-hours (8 working days) turnaround time to sort this out? I paid R999 for a service that I could never benefit from in my residential area. I want a full refund immediately, with no excuses!!!