Welcome back to the community and sorry that it couldn't be on better terms than this issue with your wife's sim only contract.
I would like to take a further look into this but would need for you to pass account security to be able to do this, I will send over a private message in a moment, please look out for this and we can get started.
Thanks for coming back to me with your details in a private message @boswelluk.
The issue is being looked into by the fraud team due to the volume of text messages that have been sent, this system has seen this as potential fraud and has suspended the services, while it was investigated further.
We should have informed you that this would be happening rather than you discovering it for yourself, I have looked into your account and the restrictions have now been lifted from the account, so your wife should now be able to use her phone again.
Please can you try this and let me know if she is able to send messages again.
I'm glad that your wife can now send text messages but not good that she cannot send them to you. Is your wife able to message and call you?
I have looked into both of your numbers and all the settings seem to be correct and as they should be to get a full service. This may not work but would you both be able to restart your handsets, to see if this can help at all?