Taking money for a service they can't provide

On 2 July I bought an uncapped high-speed 5G package from Afrihost. They charged me a pro-rata rate of R918 upfront for the month ahead. But despite the router arriving 2 days later and being properly installed, I couldn't get online. After support eventually decided it was an MTN issue, which they escalated but never fixed, I requested cancellation and a full refund. This was on day 5 - well within their 7-day returns policy. The LTE department processed my cancellation and confirmed I was within the timeframe, then sent me to accounts for the refund. Accounts claimed they needed more info from LTE, causing endless delays, and then suddenly told me the 7-day policy didn't apply because I hadn't followed a separate router return process that nobody had ever mentioned to me. When I tried to complete this return process, they hit me with another R249 collection fee - despite the fact that their service never worked in the first place. Basically taking my money and not supplying what was agreed in return, and then treating me with complete disdain.