Unprofessional

I have been getting sms's from Landau Attorneys, or someone claiming to be them. Seeing as I haven't received any legal documents pertaining to what they are claiming. A lady has phoned me twice to arrange payments, and each time I have asked for documentation. I was promised both times that it will be sent to my email account. So far no other communications have been made and no emails received. This is all very unprofessional as well as weird... How am I expected to make payments without any legal proof?