Have you ever seen in the news that someone signed a Buyer Representation Agreement (BRA) with an agent (sometimes without even realizing it!) and then bought a home without them representing them? They now owe their agent money, multiple thousands, and they never even know that was the case. Others have signed a BRA and they decided they didn’t like the agent and wanted to work with someone else. Well the agent didn’t let them out of the agreement and they had to wait out the time period before they could buy or they’d owe that agent commission?
These are scenarios that play out across Ontario. This has made many hesitant to sign a BRA. So what happens if you choose someone to represent you and you change your mind? Can you fire your agent?
Legally speaking, you can’t. You are bound to the contract that you signed and it would be a lengthy and potentially costly experience to go through the courts to get it terminated. 
So what are your options?
First, you can asked to be let out of the contract. Some will if you don’t want to but this is up to the agents goodwill essentially. Second, your contract is technically with the brokerage and not the individual agent so you can go to the Manager of the brokerage and asked to be assigned to a different representative. They don’t have to assign you someone else but some will. If you don’t want to use that person the only other option is to wait until the contract is up. That can be months sometimes. 
Personally, and this is specific to me and not RE/MAX Chay, I do not require my clients to sign a BRA. That only comes when we are making an offer on a property because legally I need to have proof I represent you in the deal. So if at any point you want to stop working with me, guess what? You just stop working with me. No strings attached. It’s  a clean break.
If we have signed a BRA and you don’t want to work together anymore? Guess what, I’ll sign a termination. I don’t want to work with anyone who doesn’t want to work with me anymore. This is why I also like to meet all potential clients before seeing homes together. We can get a feel for each other and see if we think it will be a good fit for either us. Buying a home is a lot more stress free and fun when we both like each other and you trust that I have your back.