Afrihost abused my credit card

I registered with Afrihost foe Fixed Wireless Internet. There was some doubt about whether the coverage reached my house I signed up for a SIM card only as I have a new LTE Router I was told that I could cancel with no cost within 7 days if the Sim card didn't work It didn't work When I cancelled on the 3rd day I was charged R999. Afrihost refuse to answer my queries, verbal and email BEWARE of Afrihost. Their service is not what it was.