WI-FI suddenly not working?????

So disappointing. We have had fibre since April and never had an issue. Since last week we have not been able to connect to our Wi-Fi. Now it shows that we don't have an account?? I can show you all the statements that we paid, never mind your call centre sending us from pillar to post. The after sales service is BEYOND useless. I WANT MY WIFI UP AND RUNNING!!!!!!!!! Its shocking how bad your service is.