The Bitcoin scripting language actually does provide a great foundation for payment reversibility and solutions for this do exists. I'm working on one such solution, https://www.bitrated.com/.

Edit: We're about to re-launch Bitrated in about a month, with a new system that's been written from the grounds up. If anyone reading this is interested in seeing what we've been working on and would like to provide some feedback before the public launch, please contact me (email in my profile). </shameless-plug>