Same happened to me,we have a Blue badge as my wife is disabled and needed to go to the doctors clinic. No spaces even in the disabled bay so we parked on a taxi rank for less than 20 mins.
Came back to find a parking ticket. We disputed it and told them about the Blue badge and lack of space, no good . Even a Blue Badge holder can not park on a taxi rank not even in an emergency.
A Blue Badge holder can even park on double yellows for 4 hours but not on a taxi rank for even a few seconds.
Do not bother to appeal there is no point.