Using the NW CofC quoted above, in my lay opinion it is clear you are not entitled to a refund having already agreed to 'be searched' (explicitly or by omission).

The only chance would be if the subsequent changes in the (unspecified) search process were deemed to be either illegal or unconstitutional. As has been discussed in many previous threads, the courts have held that airport searches in their original form are exempt from 4th Amendment provisions. I don't think there has been any challenge that the current pat-down aspect constitutes unreasonable search, and although I wish someone would I expect the court(s) would conclude they are OK too .