ADT blocks valid billing query

I am and ADT client. I have a billing query and the only form of contact I can access, because I am out of the country, is via their webpage that requires excessive information and will not accept valid information. It will not accept a valid postal code (but it will accepte a ficticious code) and it will not accept a valid phone number. This completely blocks me from querying my bill. I believe that I have been billed for services that have not been provided and there is no way the system will allow me to query it.