Just travelled to Dubai and paid extra for 2 “skip the line tours” to burj khalifa and the mall aquarium via TA. Turned up to both and found no prioritisation. The first one actually took an hour to get to the top. The local agents has ignored my complaint and I checed the internet and apparently there is no recourse or no way to complain to TA or Viator about the clear misrepresentation of the offer so you won’t get your money back.