Good Morning,
We understand your frustration, and we are sorry about it.
Viator is selling our product, but we are not in charge of the tickets delivered by them. Therefore, when there is a problem, we can’t do anything about it. Only Viator can assists you and delivered the good ticket.
There were a problem on the system when you purchased your ticket, leading to you receiving the wrong one.
Our operational team let you in on Friday evening, so you managed to do your visit anyway, and that is the most important. We hope you enjoyed it.
We are working on solving the problem with Viator, in order to avoid other problem like yours.
Best regards