Hi Armishaw. I am having a similar issue to you. I spent most of the day yesterday on the phone to BT because I couldn't use my data, couldn't receive calls (when anyone tried to ring, they'do be greeted with the message that they have dialled an incorrect number) and couldn't receive text messages.
The data and call issues are now sorted but still cannot receive text messages. I have tried speaking to BT customer services about 3 times yesterday, including BT live chat and still am clueless with the issue. Frustrating that no solution has been found after 2 days.