I can't help but feel you expect a lot from a small bike shop. Why not phone and save the irritation?
I expect that if they supply an email address, they should read their emails.
If there is a contact form on their website, they should check messages coming in from it.
If there is a phone number, they should answer the phone when people ring.
If I ran a busy company, I would prefer initial contact by email because, as Classic suggests - it isn't
YOU - ANSWER ME NOW!, it is
Please get back to me when you can...
I don't like voicemail so I turn it off on my landline and mobile. I don't let people leave messages which I would never listen to!