Horse Racing delaware park

been betting horses for years never seen this at a race track played a pick 4 at delaware park on wednsday aug 18 hit the first 3 live with 4 horses in the last leg 9 horse field there is 3 late scratches 20 minute delay reduces the field down to 6 horses they cancell the race why cancell the race with 6 horses no weather issues they continued with the rest of the races paid a consolation of $25 for all i had the first 4 favorites paying $200 $230 $400 $460 feel cheated can anyone give me a answer

Source