Worst WiFi experience

I recently upgraded my home WiFi. It was delivered on 14 May and immediately after the cooling off period the problems started. The first time I reported it they synced it and it worked for one day and since than I can’t use the WiFi. I work from home and I depend on the WiFi to give me connectivity. I logged a call and they said they wouldn’t sync again they needed to investigate. In the process the call centre people did not help with my frustration. I will be billed for a full month for a service I can’t use. This has been financially draining on me as I have to get data on a daily in order to work. A technician called me to say that the issue is coverage and therefore the contract will be cancelled with no cancellation fee as they did not test the signal prior to selling the product. I just want my confirmation of cancellation so I can get another service provider. Saturday is day 14 of no internet and I want recourse for all this. No TCF was practiced in this instance. All I get we apologise for the inconvenience, that is costing me daily?