Visiting Arizona with my teens. We thought we booked a tour for Antelope Canyon to find out that it had to be confirmed with the vendor. The next day we find that date was unavailable. They did offer a date that we could use but I wouldn't have done it had I not already done all of the work to book it.
Next we book a Jeep tour in Sedona. A confirmation email is sent however I thought I'd call the tour company to see about a meeting spot. They informed me there was no reservation for us nor could they book one and to reach out to viator. Thanks for pissed consumer having a phone number because viator doesn't offer it on there website. I then call viator and of course there is the "manadatory" hold time. 12 minutes before I reached the English is a second language call center. After 4 triies explaining what happened I'm put back on hold to verify with the vendor. 10 minutes later the agent is back on the line saying they can't reach the tour company. I voiced concern over the validity of the booking at all and I was again placed on hold. 10 more minutes and the agent returned. Now they want to offer a different trip. I declined. I was told they were processing a refund and it would appear within 3-7 business days.
Short story: don't believe it if they claim availability for what you want. Twice they blew that with me. Also I think any reputable company is willing to post a phone number. Lastly I can't stand non American based call centers. Call lasted 51 minutes. Viator is not alone with the call center BS.
I hope this helps