You can start the refund process using this link, but you are required to provide reasons according to the rules of Envato.
We recommend that you first get help on the support forum.
We can consider refunds based upon the particular circumstances of your case. In practice, we usually require that you have found a technical fault and that we are given proper opportunity to verify sufficient information about any faults which you believe you have found (and that they are in our theme , not something else), and to fix them within a reasonable time period.
If we cannot do this through our fault, we will provide you with a refund.