Telus charging tax on credits?

No. Standard practice in Canada is to omit sales taxes when specifying prices and discounts. Pricing information published by retailers here never includes sales tax. If Telus includes sales taxes in its discount amounts then why doesn't it include taxes in its published prices? Including sales tax in discounts and refunds BUT NOT in the published service prices is obviously a deliberately deceptive practice that is intended to makes discounts seem larger than they actually are in relation to service prices. To pretend otherwise is clearly communicating in bad faith. I have never encountered any other business that does this.