We have been struggling since February 2024 with our fibre wifi

We have been struggling since February 2024 with our fibre wifi. We are offline at least one week a month. Being offline every month. September we had a problem again that was found to be the Vodacom modem. October it's still not replaced and we have been offline since 16 October 2024 until now. They keep on signing off on service reports with the note that we cannot be reached. After getting the number they phoned, it is a landline that we had disconnected 8-10 years ago. On our fibre contract we only put two cellphone numbers, mine being the one who will contact them with queries. Nobody phones back. I was told they will replace the modem which seems, is not compatible with the Evotel system. That is already a week ago ... no phone call, no technician.