You MAY have a cause of action against the agent and his or her employer, for either fraud (a knowing misrepresentation of the deductible) or for negligence (carelesslessly telling you the wrond deductible or not securing for  you the correct policy). A key factor, though, will be what information was included on the policy and any addenda to it (or summaries of it, like a coverage summary) which you received from the insurance company when you bought the policy. If the deductible was correctly disclosed to you in the policy itself or in coverage binders prior to you signing and actually buying the policy, then you might not be able to recover: in that case, you would have been provided with the correct information and would have had a chance to either challenge the deductible and try to get it changed, or to walk away from the transaction. People are presumed to read and agree to what they sign their names to; if  you had the proper deductible disclosed before you accepted the policy, you may be held to having agreed to it.