Are you a prepaid or postpaid customer? When you mentioned “it doesn’t appear to be activated”, was that message in your self-serve?

As  well, have you tried to reset network recently?

Monthly customer. Data on phone still shows old data, but Self Serve shows that the current plan is the new one. I have not reset network as I am unfamiliar with that.

A phone reset of network settings normally would help to ensure the phone receive latest carrier settings. depending on your phone model, it is normally an option in the phone settings reset.

If you saw a data limit on your phone, it is a setting set by user (not carrier). You could change the data limiter Normally you could follow this to remove the data warning

1. Open your phone's Settings app.
2. Tap Network & internet Internet.
3. Next to your carrier, tap Settings .
4. Tap Data warning & limit. If needed, first turn on Set data warning.
5. Tap Data warning.
6. Enter a number. To switch between megabytes (MB) and gigabytes (GB), tap the Down arrow .
7. Tap Set.

This does seem to have been the fix, I did not know this! Thank-you very much!