I bought a theme but it never worked. I contacted tech support but no response from them.
Considering you’ve purchased the theme from ThemeForest (and not downloaded from Envato Elements), it’s always best to try and reach out to the author of the theme for support IF the item is supported (you can check if the author offers support in the “Support” tab of the item).
If the author states that they provide support for the item and you didn’t hear back from them you have two options:
Wait a bit longer. There are authors that do not work during weekends or that may have some issues going on right now. You can wait a bit longer, and maybe give them another message to remind them about your situation.