Did you complete the shop report and submit it by clicking I'm Done?  Look in your Completed Shops list.. If you completed and submitted the shop, it will be there.

Didn't complete and submit the shop report yet?  Check your incomplete shops list. If it's not there, chances are the time limit the shop has expired. 

While doing the shop, make sure you pay attention to the time limit (the remaining time is displayed at the top of the shop form, and the expiration time is also displayed next to the shop in your incomplete shops list). Please be aware that the timer starts running immediately after you've claimed it. It's always a good idea to check your incomplete shops and pay attention to its expiration time.

If you won't be able to get to the location and complete the shop within the assigned time, or that if the location won't open for another ten hours, you shouldn't claim a shop that has an eight-hour time limit.  We don't penalize shoppers who fail to complete one or two shops, but if you do this often (or with a large number of shops), it can affect your reliability rating, so please try to avoid it.