In order to make a difference, you are going to have to begin by acting rationally and objectively. Although you may feel very emotional, spouting off at the manager isnt going to change anything, but get yourself a restaining order. Now, you cant be much help if you get arrested! haha
Ive been doing petstore inspections for years.
Heres what you do:
1. Document every account of neglect
Take pics, write as much info as you can for each pic, incl species, if any were dead, what EXACTLY was wrong with the husbandry, what needs to change, how many animals are being effected, ANYTHING you can think of that is relevant to the neglect.
2. Take it to upper management. Corporate headquarters. Ive got some contact info if you cant find it on your own, but its pretty easy to find online. Make sure they realize the severity of the flaws, and your seriousness about following up until they are corrected. Fax them the pics, along with your report. Give them a timeline, and make sure you follow up.
3. If the corrections are not made, then you must contact you local spca. Depending on where you are, there could be other groups in charge of animal cruelty/ neglect cases. Just call around and find out.
Once youve made contact with the appropriate group, fax them the info which you sent the pet stores corporate headquarters, and make sure you give them the names of personel, dates of actions, and ALL that information which you have collected in regards to the animals.
See that they send an officer to inspect the stores in question. Now heres the most important part...
MEET the officer at the location!!! If the dont show, follow up with an inquiry as to why an officer never came. BE PERSISTANT. It may take numerous requests before the will come. Its important that you are there to take them by the hand and show them what exactly the issues are.
Good luck, and keep your wits about you. Remember... "POKER FACE!"