Ah, it’s a brand new theme so there’s definitely not a shopify version out there. 
Hiring a developer to convert the template to shopify is an option, but it would be rather pricey (at least a few hundred dollars for a small number of converted pages). Unfortunately converting a template to a theme is a very time-consuming process that requires a lot of programming, hence the cost.
You could perhaps try asking the author for a refund, but do understand that they are not required to do so since you’ve downloaded it.
If you’re still looking for a shopify theme, here’s a link to browse and search them: https://themeforest.net/category/ecommerce/shopify