Occasionally there are problems syncing the WAV format in iTunes. In this case, download the MP3 version in your customer area (preferably via a Mac computer or PC). To sync your music to your iPad or iPhone, we recommend iTunes or AnyTrans software. After installation, you can connect the iPhone to the computer via cable and easily sync the music. (Incidentally, this is an issue with all types of music files, not just files downloaded from audiohub.)
Since Apple is restrictive regarding its audio file management, it is not possible to transfer audio files to a mobile device without a computer or iTunes.