I just went to Walmart to use a Vaseline FPC and she removed the full price on the coupon.. but then charged me tax?

Then earlier.. I was at the Real Canadian Superstore and I had an FPC for an Oral B Tooshbrush, and again I was charged a $.25 environment fee AND almost $1.00 in tax. (I got this coupon directly from Oral B as a replacement for a broken one I bought a few weeks prior)

Can anyone verify if they can charge tax or not? I was sure they couldn't... but I asked Customer Service at RCSS and she said they do.

Also, if they're not supposed to.. can anyone provide policy from anywhere it states that?


Thanks!!