You could always print them a copy of
What's Taxable Under the HST and What's Not?, available at the Web site of
Her Majesty's Government for British Columbia. The rollout of the harmonised sales tax is the responsibility of the provincial government (that's probably why federal Web sites have been unhelpful to you).
The B.C. Government has done an absolutely terrible job of rolling out information to retailers (and some of the new tax schemes are incredibly complicated), so I would suggest that it isn't entirely the fault of the retailer--particularly a newer, private retailer "new to the country," as you described above. They probably just need some more information on the matter. (And this also assumes that they know
how to remove tax from items; that can be a pain on cheaper, Costco-bought cash registers.)
Just as an example of how terribly put-together the HST is, consider this trainwreck:
Coin-operated vending machines are assumed to collect HST on a purchase, provided that the following are true: (1) the purchase is more than twenty-five cents; and (2) the customer has paid with more than one coin, except for one-dollar and two-dollar coins. The HST is deemed collected at the time that the coins are removed from the machine, and is calculated as the product of the coins collected, and 13/113. Now, don't get me wrong--this stuff should be researched thoroughly be the retailer--but let's be honest, these sorts of policies are very difficult for retailers to implement with any degree of instant reliability. (Just as an example.)
Try giving them the information linked above--it's pretty user-friendly, so there shouldn't be any problems. In the worst-case scenario that your retailer remains unwilling to comply with tax guidelines, you can always report them (via phone or letter) to your regional tax office. Without knowing which region you're in I can't give you the exact contact information, but the five main regional offices are listed on the Web site of the
Canada Revenue Agency, right
here.
