I just saw my BC home services telus bill and found out that they had been miscalculating PST and a long thread had been closed out. (https://forum.telus.com/t5/Internet-TV-Home-Phone/Did-you-know-we-been-charge-extra-on-our-billing-w...
What is going on now, is the same with everyone or just me?
So, what does your detailed invoice say about the taxes?
Generally, credits on your bill do not reduce taxes, whereas discounts do.
BTW, the link you posted is broken.