Ok i'm going to go at this at a neutral stance.
Considering I have never been ripped off by you i am not here to shit all over you. Me being a legit seller and i consider everyone on this site my friend, we all share the same interest which is skiing, i would never dream of ripping any fellow skier out there off. The fact that you did rip off someone is not the best nor the worst thing in the world, I do not approve of it, but you did however apologize, I suggest writing a more deep and thorough apology though if you even wanna earn any respect back from the people you have dealt with, i know if you had ripped me off, a half decent apology would be nice (and my stuff back)
Advice for the future (if you ever make a sale again, doubtful but maybe)
1. TELL THE TRUTH, its not that hard to own up to a mistake early before things get complicated, admit your mistake, apologize and fix it. If you sell someone something that was already sold but they still sent you the money for it, PM them and say, "hey bro, im really sorry, I feel like an ass but I already sold those to so and so, or they aren't for sale or i dont actually have those, I know it sounds unlegit of me to do but I am willing to give you a free refund/your stuff back"
2. Repeat step 1
3. Repeat step 2