You really need to stay clear of pet stores, honestly. Pet stores are just that - stores. Most don't care where their animals go, ESPECIALLY smaller animals like mice, hamsters, and rats, so your babies could end up with anyone that has the money to pay for them. Not to be harsh, but you brought those babies into the world by your own mistake, you should stick this out and find good, knowledgeable homes for each and every one of those babies, along with spay/neuter your resident rats.
Also - what are you currently feeding Nancy? And how often are you socializing the babies?