If you can’t get in touch with the owner of the store (you should of received an order confirmation email, that includes the email of the store owner - or their support email address), then you should contact your bank (or credit card company) to initiate a chargeback.
In the future, I’d recommend not purchasing from stores that don’t have a custom domain name. If the store still uses a ‘.myshopify.com’ URL, then it’s probably not fully set up yet, or is inactive. It also helps to research reviews for stores before purchasing from them – this is good practice for any purchases online (not just Shopify stores).
Seeing as how the store is no longer available (if you go to hobomon.myshopify.com), it’s likely that Shopify has already acted against the store owner, hence the closure.
I’m sorry to hear that this happened to you. I wish you luck in getting in contact with the store owner, or else filing a successful chargeback.