Not So Happy Heinys

This is the wrapper from a cloth diaper. The Trademark name is Happy Heinys like it's the plural of heiny, no apostrophe. But, on the back, it's spelled Happy Heiny's like these are owned by someone named Heiny. Now, if the official name is Happy Heinys, when you make it possessive, wouldn't it be Happy Heinys' diapers? I've seen it on multiple cloth diaper merchant websites as Heiny's, though on their official website it's Heinys. Confused yet?

I don't know whose Heinys could be happy with this!