I know this is under warranty and LBS should fix it. But this is a great opportunity to learn how to adjust derailleurs and know your bike. After the first year (as things wear, get bent a bit) you may have to adjust every once a while and don't want to pay the LBS to do that.

I once rode my bike on my former commute. There was a bicycle event with free breakfast. Naturally I stopped there. some LBS had booths with free adjustment for anyone. Nothing was wrong with my shifting, but I thought "why the hell not have a professional adjust for free". Since then I never could get my front-derailleur right since that guy screwed it up. The only thing I got for free (besides the breakfast) was the lesson that I don't let someone else touch my bicycle and learn to do it myself. Even if I don't know what I'm doing, at least I care. On a former bike (bought new) I also had to bring it back multiple times to LBS for shifting issues. The problem was, they only adjusted it on the stand, never while riding. Well, with no load it probably worked. But in the real world I don't pedal while the bike is off the ground. The owner got all weird and told me after many times I shouldn't be so picky since he lost a lot of money on the bike since I got a good price blah, blah blah. It was a shimano Deore, so it was clearly able to shift well. After I gave up on the LBS I taught myself by looking at it (that was pre-internet) how to adjust it and it shifted flawlessly for many years.

If you want to have something done right, you have to do it yourself. Obviously under warranty give the LBS a chance and show them how you shift and have them re-produce the problem or reproduce it in front of them.

Edit: after some years the sifter cables stretch out and you need to replace them. Obviously this should not be the problem of your new bike.