Similar thing happened to me at BWI 2 years ago and we waited 2 hours for a technical issue.
The compensation was a free one-way voucher which was announced on the plane by the flight attendant on the speaker not once but twice.
Soon after we got home and I planned to use them there was NO record found INITIALLY when looking at my flight purchase/history.
After much insistence the agent "FOUND" it on my and husband's record.
So insist in them looking at the technical problem and what compensation is given and find this voucher that they promised.
Hope this helps.