My Petco takes everything back no problem. Just last week I returned a harness I bought for my grand dog that was to small, I didn't even have the receipt anymore. They gave me one that did fit for the same price even though it wasn't on sale like the first one I bought. Pestsmart doesn't carry Wellness. I have a hard time getting small bags of Wellness they don't stock many, just bigger bags. Doesn't make sense, small breed means small eater in my book. Unless you have a heard of Yorkies you don't need big bags.
I did complain about a groomer at Petco, so they didn't blow off my phone call I followed it up with an e-mail. I did get a call back from them after the e-mail.