Kuala Lumpur, Malaysia
I'm not sure how, but I accidently booked the trip on the day before than I intended. The tour company even left me a message before I'd even arrived at my hotel to re-arrange it. Once I spoke to the kind lady on the phone, the tour was arranged for the next day without any extra costs.
Overall the tour itself was fun and very interesting. The tour guide was friendly, and the people we met who were also with us in the same vehicle were very nice.
I would definitely recommend using Viator and also the tour itself in KL. KL itself is such a beautiful city, and you must do the Batu Caves and Temple Tour from Kuala Lumpur!