Seller is not responding to support, direct email bouncing

What can i do? how can i contact themeforest?

It depends. - have you bought the file or is this just a general pre purchase question?

Unfortunately If it’s the later then there’s no obligation for the author to respond to general item comments and envato won’t be able to help with file specific queries

It is purchased. I tried sending a mail to the support email but it bounces, so my best guess now is the comments form also notifies on that email which bounces too.

On your item comments it’s not showing you as purchased which probably doesn’t help your case.

If hey are not replying at all then you can speak to support here