"Ordered two filters because they promised $10 off. I looked carefully during checkout for a place to enter the coupon code and saw nothing. During checkout there was no option to review my order before submitting it. So, I had no chance to review how much I was being charged, how much taxes would be, and to verify that the coupon was actually honored. Called them but wasn't able to talk to a real person. A recorded message took my name and phone number but after an hour hadn't called me back. My complaints are 1) Failure to honor the coupon, 2) Failure to show how much I was going to be charged during checkout, and 3) Failure to return my phone call."