Linda, I feel your pain. After a year of dealing with the chain slip on my Verve +2 here is my advice:
1. Immediately take your bike back to your Trek dealer and have them diagnose the issue. They will make it right. Most likely they will install a narrow wide (NW) chainring for you at no cost.
2. Have them remove the OEM chainguard and leave it off, it makes access to the chain that much easier to reset a slip and allows you to lube and maintain your chain, cassette and chainring that much simpler...you know, kinda like a normal bike? Sheesh.
I should also add that chain slips are not uncommon with bikes, it has happened throughout history and will continue to happen. But, you shouldn't need 15 minutes and tools to reset it....get rid of the funky chainguard cause slips are going to occasionally happen down the road.
Hope this helps and you fall back in love with your bike....it is a really great bike!
Best of luck
Howard