Allowing refunds on link unlocks would open a very huge list of problems:
• Users might ask for a refund when it's instead because they didn't follow the installation instructions properly
• Users might ask for a refund when it's instead because the game isn't compatible with their devices
• Users might ask for a refund when downloaded an outdated app without checking it first, as expressly asked to confirm before proceeding to unlock the download link
• Each refund would have to be processed and verified, which would involve many people (we should expect over 100 refund requests every day) and a lot of time invested in this
• Processing refunds would mean having to manually deduct the author's percentage and manually send the full amount to the buyer, which is quite time consuming and could not be done by everyone, as it might lead to people abusing this feature
I'm not here to affirm all mod apk files work, so the current system we have might not be the ideal, but I tried my best to avoid problems:
• Implementation of a rewarding poll (gives 10 SB Points every time) with feedbacks from all users who already downloaded the app which should give a clear idea to users before downloading/unlocking the mod apk to know wether it worked or not
• The notice to give a feedback after trying a mod apk (above the editor, I created a script which displays that notice only in pertinent areas of the forum)
• A system which rewards users even for doing nothing every day (we send 30 SB Points, and increasing rewards planned, simply for loggin' in every day)
• Many communication ways on the site (mobile/bottom chat, forum's main chat, forum's private chat, forum's private conversation system) which might be used from users to directly ask thread authors or users which downloaded their contents, in order to know if it works fine or not before unlocking it
This said, I'm not happy to deny your request to implement a refund system, but I hope you'll understand my reasons and all the problems related to it.