Oomph sim set up today few hours ago and makes/received calls but won’t send texts or connect to data
Having the very same issue
Really sorry you're having this issue, this ins't good.
Can I ask what phone you've got?
Are the messages you're sending normal text messages or iMessage?
Have you gone through setting up the phone here? It might be that you need to update the APN settings.
Let us know how you get on and we can assist further if needed.