At least in the US, establishing a legal contract requires more than just an attestation and agreement by both parties (verbal or written or telegraphed or whatever).

For example it’s not a contract if there is no “consideration”, a legal term meaning the parties have exchanged something of value.

IANAL, but “abuse of telecom resources” is the more likely flavor of legal hot-water you might land in. I would absolutely not worry about a fraudster taking me to court.