What to do if purchased theme has lots of errors and the author is not responding?

Hello,

What we do if a purchased theme is not working as we expected? We have contacted the author through comments, they told to send through form. We did that but no response. What can we do in a situation like this? Is there a refund policy or any authorities to help us?

Depends what exactly is wrong but if the author is not responding then you can check here https://help.market.envato.com/hc/en-us/articles/202821460-Can-I-Get-A-Refund-