Usually these exclusive representation agreements from realtors are light on termination clauses, and heavily tilted in the realtors favor. You are probably locked up for 6-12 months, with out much of a contractual way to terminate. Also, there is usually a holdover clause that says if you buy a house after the contract expires, that you found before the contract expires (even if the realtor didn't help you) you still owe a commission, so watch out for that.

You are not stuck, though. Here's what I'd do. First, tell the realtor you want out of the contract. No need for big drama, just tell him that his performance didn't meet your expectations and you would like to terminate the contract. Most realtors realize they don't want to work with someone who doesn't want to work with them and will agree. Get it in writing, though. Doesn't have to be a fancy legal document, just 2 lines on a sheet stating the contract is terminated and signed by both parties. Don't assume this is cancelled until you get it in writing. Don't agree to pay anyone anything.

If the realtor refuses, call his broker and have the same conversation. Again, don't agree to pay them anything. No cash for their time, no percentage of future sales. etc. They don't have much invested in you, so they will probably let you go.If you really want out and they really refuse to let you out, you are stuck, and will have to play hardball to get out, but it likely won't come to that.