The main store is an online entity only. Each vendor has their own contact information which you can get from their store.
The most direct way to contact us is at firstname.lastname@example.org because server email can be unreliable so this is a direct contact address.
Please put in the subject line 'Mountain Flea Question' so I will know what it is about.
You can also look up the domain name using Whois and get more information.