30 miles isn't a ton- that could of been only 1 ride.

They don't need to know how many miles.

They sold you, blatantly, the wrong size bike due to lack of fit knowledge/laziness.

I am 5'6 and I am stretched out on a 50cm frame. Granted I have long legs and a short torso but still.

At only 4'11 you should be on a 44cm(as my educated guess, I used to work in a bike shop) a 47 would be stretching it. I know Trek doesn't make anything smaller then the 47 but I would imagine you being on a 47 with a 90cm stem as the longest option.

I would take it back and demand that they exchange it out for the smaller size and include a proper fit.

You should never buy a road bike and not have a fit done.(that is the stores fault if they don't include a fit)