What's wrong with sticking a wide climbing cassette and/or a compact crankset on this bike? You can change the handlebars too, and if you haven't had it too long maybe the shop will even trade out for free? Did you take a tape measure and double check that the shop duplicated your fit correctly? Did you try your preferred tires or are they stock; if stock, then switch to your preferred tires. Maybe try a few things before giving up on this bike. Good luck!