Yah definetly a defective bearing would "howl" any time the vehicle is in motion. A defective CV joint would make a bunch of clicking noises, especially when turning at full lock. I guess the question is, what is the sound like that is coming? Is it a squeak type sound (like brakes?), if that is the case, then as everyone mentioned, it's the uncompatible materials in the disc rotor and the pad that cause the noise or poorly lubed shims. One thing I always tell individuals wanting me to repair their brakes, is to go buy the OEM stuff from the dealer, no Pep-Boys, Kragen's, Autozone, whatever...crap as they DO squeak from uncompatible, or rather poorly blended composition materials (organic vs semi-metallic compounds).

Another thing to check too is the brake wear indicators, make sure they are on there properly and securely. I use the "IB" rule (something I made myself) and that is Inboard Bottom for location of the indicators (I call them squealers ). As far as taking them back, brake pads I know from part stores are warrantied for life, but I don't know about actual money back. It never hurts to try, good luck!

Whenever you get new rotors, what I do is take brake cleaner and spray the back and front of the disc and wipe. You DON'T need to do this for pads however. Make sure you lube also the caliper sliding bolts (not the threads however, just the smooth portion that goes inside the caliper housing), never really seen this to cause noise, but it helps.

And not trying to insult your intelligence, but try to be gentle with the brakes for the first 200 miles as they break in properly, an often occurience of out of round or "warped" rotors is people freakin slam their brakes within the breakin period and wonder why it happened so quickly.