Love Amazon! Huge selections. Fast shipment. Have never had a problem. Not sure how it is to work w their customer service - because I've never had to. Hassle free shopping w excellent service.
Allivet is the WORST pet supply company! As others have noted, to get through on the phone is practically impossible. Their ship time is Very Slow. If you want something shipped from them, plan way ahead. Better yet, don't use them. I'm done.