I was flying BWI to ORD onto LHR.....

I was bumped because of an oversold flight, at my request the TA put a notation in the PNR that I was a great volunteer and to post the full trip to my account.

A phone call to the EXP desk a couple of days later got me a full qualifying credit for the MR to London, a complete refund of my ticket plus the $300 bump voucher I received at the gate.

One of the few times I did not have to fly to get the full credit. ^