I don't think you are very likely to get out of the contract but you might get a different realtor from the company assigned to you. When we sold our last home, I signed a three-month contract (would never do longer) with a very nice woman from our church. She neglected to tell me, however, that she was thinking about switching agencies. When she did less than two weeks later, the owner of her old firm came out to explain to us that the contract was with their firm not the realtor and that he personally would do everything possible to see that we were well taken care of, but that he was not cancelling the contract. I ultimately was not happy with the service and became a demanding, complaining customer. When the three months was up, he showed up at our house with a new contract with them and an offer on our house. I refused to sign the contract as it was and ended up signing one valid for one week. We ended up with that buyer, though.
At closing, they were both there with their hands out waiting for commission -- the original realtor (who got the commission on our new house through her old agency) and the owner of the real estate firm who collected commissions from both houses and was listed as the selling agent.
Ironically, the agency owner and his wife built a house in our new neighborhood on our street. Whenever one of my kids has something to sell, I send them there and they buy the smallest thing -- and he personally collected over $10,000 on our two houses.