/r/relationship_advice

Had to leave my childhood best friend in slavery and wasn't able to keep my promise to come back and save him in time. Found out he was alive years later when he saved my life. Now he's my junior coworker and also hates my guts. I let him get away with murder (literally) and buy him lots of expensive things but it hasn't helped. How do I fix this?

Edit: Suggestions to explain why I didn't make it back to rescue him will be ignored.