There are multiple ways to connect with your customers using the Hubgets Page.
You can either send them the link of the page in your email signature and ask them to contact you there whenever they need your assistance, or you can import your customers details in the Hubgets People manager and simply send them the message from there. Your message will be an invite for the customer to connect with you via the Hubgets Page.
People can contact you on your Facebook Page only if you accept the contact request.
Hope this helps!