Tricking clients to update details, meanwhile sign contract

Last year they contacted us to ask us to update our details on their file that will be sent in order for us to get a free updated listing. then later realised they ******* me in signing something that was barely readable. then in February they kept contacting me for payment of which I was unaware of signing a binding contract. Real **** if you ask me. they have not per email given me option to fill in and sign their contract or per email let me know that I will be liable to pay them for a years contract. Definitely **** business