wrong invoice

am so disgusted by the service I received from ICM,,,they made a mistake on a invoice send to me,,,but they wanna keep me liable for that money..So When I phoned phone to a lady called Terry she is very rude very unprofessional.She actually told me to escalate and take the matter further.I don't ever wanna deal with someone like that,that does\nt know how to address issues.Then I spoke to her superior who tell me to pay fees that i haven't received an invoice for.BAD BAD BAD CLIENTS SERVICE. "