I have submitted issues related to a Geneva tour to Viator's Customer Service department with absolutely no response despite 4 messages over 3 weeks. Nothing.
A truly abominable way to treat customers.
The issues were related to pricing (Viator is apparently a third party and I could have booked directly for less), bus conditions (dirty, and I included photos) and itinerary change ("Cheese and Chocolate tour" was only cheese, plus a castle as a substitute for no chocolate, which you didn't find out until you boarded the bus).
I am shocked to discover that TripAdvisor purchased the company. I would expect more.
Reviewer is in unhappy mood. This person is quite happy with easy to book and stated that there is a room for improvement of customer care and unresponsive. Please immediately contact the author of this review to discuss poor customer service of viator tour and associated monetary loss in the amount of $100. Viator needs to issue a partial refund according to poster's claims.