Wirelessly posted (BlackBerry9630/5.0.0.591 Profile/MIDP-2.1 Configuration/CLDC-1.1 VendorID/105)
What was the "nominal" fee that you paid the TA to do the cancel?
Generally speaking the OTAs follow the rules of the issuing carrier so if B6 has a 4 hour rule then so would Orbitz or Travelocity.