Phone Call from amazon

Hi there,

I just had a phone call to my landline from amazon asking if I could confirm an email address that I don’t use very much. I haven’t used it in years and it is connected only to my eBay account. When I questioned him why he had it, he said I must have used it to log in with some time. He knew my name and seller account name.
the number he rang from was 02038852699, wasn’t amazon when I rang it back.
Not sure what to do know