Man, they support the moped community. That's it. I don't care how often they fuck up, I don't care if they don't have parts in stock, I don't care if it takes them a month or two to get a part to me. I don't care because they're busy keeping hundreds of other people riding. For me, that justifies forgiveness and patience.
Running a business is risky and hard, especially when you have people doing the things cockatiel mentioned. The fact that you haven't had a parts order fucked up yet suggests to me that you haven't been ordering or buying moped parts for very long. It's almost a part of the scene, and you just have to learn to roll with it. This isn't people trying to run a slick corporation, or develop a bitchin business model. These are people who love mopeds, and want to help other people who love mopeds.
That said, I'm not trying to hate on you, or call you out, or chew your ass in public. I'm just saying, a little patience, forgiveness, and understanding goes a long way in developing lasting business relationships, not to mention friendships with other people who share your hobby or passion.