Dominican Republic--we had 2 children in tow and were denied after being stamped/paid w/departure fee--when we left, exited thru immigration--they canceled the stamp--did it again the next day and the next day
finally went to alternative airport (via rental car) 2 hrs away and got on return flight (this was our airline)
GA has no responsibility but typically will assist after rev pax are gone (if possible)
Plan B/C/D is my responsibility and I always try to be prepared
I agree with NO BAGS--like shooting yourself in the foot, period.
Coupons--watch them carefully--I've agent take the wrong one--your responsibility to get it back if it's been held until boarding (that was OAL)