In Boston, the rate that you are quoted isn't the actual rate you should pay.

It seems like you just had a ride on the Pike through the city, and that the driver didn't end the trip when dropping you off and instead drove back towards Downtown with your trip still in progress.

The Q+A should help you get the money back (it's annoying but it works), and if you want you can probably have the driver get a call from Uber HQ.