Until recently apps that have been refunded couldn't be redownloaded from the App Store and I think they couldn't even be bought again.
However, I recently noticed that these apps now show the cloud symbol for being downloaded again free of charge like any other app that has been bought.
Is this just a problem with my Apple ID or is it a general problem? Also, if it is a bug, has it already been reported? (I don't have access to the developer forums.)