As long as it's not a chain store, they should be able to help you. But that does not mean they will... It should be fine for a little while, a month or so...
Do some reading on how to properly frag, but the basic idea is you would hold the Yuma frag out of water for a few seconds, which should make it reseed enough to expose the zoo polyp. The zoa will also close up. Take a very sharp blade and scrape the zoo off the yumas frag plug. For the best chance of success you should try to cut the plug itself so you don't actually cut the zoa itself. Get a fresh plug put a small dot of gel super glue on it, then using a pair of tweezers place the zoa on the dot of super glue and allow to dry for a few seconds... Dip in a small cup of tank water and then your ready to place it in your tank.
Post a better picture of the zoo, I can't tell what it is...