by Captain Sensible » Mon Jun 16, 2014 2:47 pm
Betfair allow you to cancel inplay but you do need a valid bet ref in the Bet Ref column as that's the bet it cancels. In your data the bet ref is showing as PENDING so I guess you fired the cancel too early before the Bet Ref had been returned by Betfair for the original bet due to either some lag or maybe the inplay delay had finished