Wow, a ten gallon fish tank is small enough itself, never mind with SEPARATORS!
I don't know if it's against the law to not provide animals with enough room or not, but maybe contact some kind of
animal control authorities like a SPCA or
Humane Society near the store. Also, make sure to tell your friends and family not to shop there (at least for their animals) because of this.
That is VERY shocking, and almost sounds unreal! Pet tores are only out for profit.
I can only imagine what kind of crap is on their care sheets, if they even have them! Also, pet stores like that often have sick animals. Selling sick animals is illegal, and is finable, at least in PA.