Cancelling a Listing

I haven't seen the contract involved, and I am not a lawyer.  But the general rule is that you have the right to cancel an agency whenever you want to.  I don't think you need any reason.  You might be held responsible for the agent's expenses, but that should be all.  You must understand, though, that you made that contract with the company, and not with the individual agent you dealt with.  Your first step should be to talk with the managing broker in that office, to discuss the situation.