5GB plan no longer in service?

I have a daughter that had blown through her 5GB limit. I was under the impression that after 5gb that it was throttled. To my surprise, I cannot text her this morning (SMS, not RCS) as I get an automatic reply "unable to receive message - Message Blocking is active". Does Mint still throttle the data, or did she use so much data that they had shut her plan off until next month?