We have used viator for several years in different locations and overall we enjoyed their services. But, on a recent trip to Europe we saw a different side and their poor customer service. We booked a one day tour of Paris and we were staying outside of Paris. We noticed signs on the metro that the day of our tour there was a one day social event work slowdown. On the morning of our tour we checked and the limited trains so could not get us to the meeting place in Paris in time. We made numerous calls to the tour agent without success and even called viatour and they told us they didn't know about a strike and it was our responsibility to get to Paris. We stopped in our hotel and an employee whelped us for an hour to finally contact the tour agent who told us basically you get here or lose your money. The hotel concierge realized it was the same company they use for tours and they had cancelled paris tours because of the transit issue. We ended up taking a tour with another company that was great and 3 weeks of fighting with viator and we ended up calling our credit card company to get us a refund. Horrible customer service. Later in the trip we arrived at the Rome port and had scheduled a transfer from viator to our hotel in Rome. When we booked the transfers, we could not schedule a time as we didn't have a disembark time. 2 days before arrival we tried calling the vendor but it went to a non working cell phone. Even the ships crew tried numerous times. Upon arrival, no car service. we waited an hour with multiple calls to the vendor and finally crew member go through on their cell phone and were told a car was there at 7 and waited and then left. They told the vendor that the ship was just getting in at 7 and they hung up on the crew member. We ended up hiring a taxi and 2 weeks later still fighting with viator.