"Zero" return policy? Sorry LiveBait, not true. People (including myself) have returned/exchanged things at Sea Sports many times over the years. Their return policy is no more restrictive or liberal than 99% of the dive shops in this country.
The mouthpiece thing is from SSI and it is indeed confusing. Lots of students forget to bring the mouthpieces they purchased so they "borrow" them from a large box of leftovers thats sitting by the pool. They also have to keep a large bag of zip ties on hand because students are always breaking/losing the one that came with their new mouthpieces.
I won't be surprised if the whole mouthpiece thing goes away soon...unless its some kind of SSI mandatory affiliation requirement.