"J&L Aquatics guarantees that your live goods order will arrive to you alive. In addition, we guarantee that all livestock purchased from us will remain in alive for a 24 hour period after arrival. If in the unfortunate event this is not the case, we require the following: "
http://www.jlaquatics.com/phpstore/s....php#guarantee
Their full policy is at the link.
I'd assume if they will guarantee an animal for 24 hours after shipping it, that the same would apply if buying in the store.
I'd give them a call.