Webafrica and Vumatel have zero care

I paid for fibre installation and it was installed only to find that it has connection issues. The login details they cave me are not working. The wifi name is not appearing when I search for it. It has been close to a week now and I do not get assistance. I have been chatting to their agents now and then but still they can't resolve this matter. I work from home and this has a big impact on my job.