Tickets canceled with Get your guide

It means that the company running your tour couldn't obtain tickets. Since they are refunding you, it's not a scam but it's unfortunate, will cause you more work, and has happened to others. Hopefully someone will post the website so you can buy directly without a middleman.

Unfortunately, I’ve seen this happen quite often. Basically these places don’t always do real time booking. A lot of them are taking a reservation and then trying to match you up with the tour operator and when they can’t do it this is what happens.

Which is why, if if it all possible, I recommend booking direct if you can. If you can figure out who the tour operator is, you generally have a better shot of this not happening. Because obviously the tour operator would rather use their customers and not pay someone like get your guide or Viator a commission.

Just to note, though, that while booking directly with tour operators is usually preferable to 3rd parties, we've seen operators themselves cancel tours. It's most common with those that include the Colosseum's underground, and usually because they sold tickets they hoped to be able to obtain but were unable to. Just a few examples:

https://community.ricksteves.com/travel-forum/italy/colosseum-underground-tour-cancellation
https://community.ricksteves.com/travel-forum/italy/underground-colosseum-tour-cancelled
https://community.ricksteves.com/travel-forum/italy/colosseum-night-tour-cancelled-2-weeks-out-what-are-other-options
https://community.ricksteves.com/travel-forum/italy/colosseum-underground-palatine-hill-and-roman-forum-skip-the-line-tour-cancelled
https://community.ricksteves.com/travel-forum/italy/colosseum-forum-palatine-hill-tour-canceled-6-days-out-by-the-roman-guy-tours-any-options

Thanks to everyone for a reply, makes my feel more at ease. Going to try to book again but direct, Thanks again