This is a booking company, not a tour operator. We purchased tickets for a Thames River afternoon tea cruise on Bateaux London through them. Were turned away by the tour operator despite having confirmed tickets through Viator. Apologetic Bateaux representative explained the cruise had been sold out for weeks and that Viator had sold tickets for sold out cruises before despite efforts from the operator to get them to stop. She could not get Viator customer service on the line to assist us. We were eventually turned away in jackets and dresses to find a last minute alternative for afternoon tea in London. An awful way to start our trip.
I received no reply initially to my online complaint to Viator. A call to US cusromer service on my return revealed that they approved a refund 10 days after my email. No other follow up, no apology, just quietly giving me my money back for the fraudulent tickets they sold me. I can't muster much gratitude over them not outright stealing my money. Avoid Viator at all costs and book directly with the tour operator.