We have put together a short survey to capture your feedback in terms of what BT can do when you experience home Wi-Fi issues. We would appreciate it if you could take a couple of minutes to complete a short survey. Read more from here, Fix my home Wi-Fi
If you're using an iPhone you might need to check that your old number is saved in your settings, as this affects iMessages/facetime:
Thank you all for your responses.
I finally hit through to a BT Technician and we tried all the usual steps without success. He finally advised that I should backup everything and perform a factory reset. Problem Solved.