EXTREMELY VERY FRUSTRATED

I signed with CellC Festival Mall for 2 gig data contract on Sat the 20th. little did I know the hell n frustrating time I was letting myself into. I use internet everyday for my business. From same Sat when I arrived at my house I could nt open a single site despite full network strength. I called their customer care for assistance in setting it up but still nothing was coming out of it. Eventually I took my laptop n the modem to 1 IT specialist I know and it turned out there was nothing wrong with the installation as it was working fine at his place & some other places but at my house it can't. their customer care committed to address the issue within 48 hours & gave me ref *** & I also gave them my GPS coordinates. But still nothing is coming out of it. I called F Mall branch notifying them it will be fair to cancel the contract & return to vodacom as I can't connect but they r having none of it & they r telling me I ll have to pay penalty n ll also forfeit admin fee I paid which is unfair as they r failing to provide a service. my business is suffering now as I can't email invoices, advertise etc. F Mall insist on booking in modem 4 repair bt there is no wrong with it.