purchased 1 year platinum membership “discount” and was still charged the full $100

If you pay every month, it costs s lot more.
The above are prices in US $.
12*$6.67 is $80.00 Over a year, that costs a lot less than paying $10.99 per month for 12 months , which is $131.88.
However, you live in Canada, right? So your price would have to be paid in Canadian dollars.
One Canadian dollar is only worth $.0.74.
So your price for the yearly payment would be somewhere around $ Can 108.76.