NAC - on-line question

[tihol tiholov]

Sorry for NAC but since there are so many web-savvy members I'd like to
ask:
How do I find the whereabouts of an on-line business, e.g., their
server, or how do I track them down through their E-mails.  I haven't
been ripped off, on the contrary, they are hesitant in selling me
airfare I want quoting inability to take my payment (credit card).

I'd appreciate very much if someone's willing to help (off list maybe)
and will give details.

Tihol