I have used the wish and geek app for a couple years now, i have on several occasions gotten refunds for items not being what is pictured or for not being whats described, one time i ordered a keychain and got nose rings... and also for items being super late.
Are they a scam? If so i believe its a legal one, i may be wrong but i would assume all sellers must agree to certain conditions before they can be a seller, and if tje seller reads it, it should describe all the legality of the system including refund policies. Now if i were attempting to start a business and was investing what i deemed alot of my money, i would undoubtedly read and understand every single sentence of how my money or valuables were to be handled. If it is a scam the sellers should be mad at themselves most of all for not doing there due diligence and research.
If this is to be your lively hood you should make sure the risks are acceptable to you. Now if there is no such legal agreement and they lie, even if by omission, then i have every confidence that sooner or later the website will be dealt with, weather by being settled in a court or by being completely shut down. If it's available on google play then its been deemed safe by whoever checks these apps out, and while some baddies manage to get through they get caught and shut down.
As long as this app has been around its probably pretty legal. Just my opinion.