such numbers in the USA are our soc sec number as a private individual or a biz number of some kind

call them up, I suspect it is something like that..they just want to track it to you as an individual..

when I got such calls ...all I had to do is prove I was me in the above manner, and address, phone number and usually they had a fee involved (sigh)

good luck.not sure how this applies in France ..but how it works in my part of USA