Amazon 10% Subscription error?

Hi all, due to boredom I thought I'd pay attention to an email from Amazon regarding my subscription for body soap. First, let me get it out of the way that I do know that for the current price I am paying, I already am having a good deal out of it so save it if you want to point it out. :) They itemised my order and I thought I'll double check it since they mentioned there was a price increase. That's when it got confusing.

NIVEA Crème Soft Soap Bar, 2 x 100g
Quantity : 5 ($1.99 each)
ORDER PRICE
$10.93 (after 10% discount)
Item price has increased from $1.64 since your last delivery.

Dove Beauty Soap Bar Sensitive, 6 x 100g
Quantity : 2 ($6.54 each)
ORDER PRICE
$14.40 (after 10% discount)
Item price has increased from $5.85 since your last delivery.

If you do the math, whoever processed this is wrong.

Nive soap: $1.99 x 5 = $9.95
$9.95 - 10% = $8.955

Dove soap: $6.54 x 2 = $13.08
$13.08 - 10% = $11.772

I figured what was done here is they wrongly added 10% on the price for both items instead of deducting it as part of the subscription discount.

Nivea $9.95 + 10% = $10.945
Dove $13.08 + 10% = $14.388

I had my coffee already so I think I am on to something but please correct me if I am wrong. I have emailed them already as I don't want to be on the phone talking mathematics to a consultant as I believe it's easier to read it than to hear it over the phone. And lastly, to anyone who has a subscription I suppose it might be a good idea to recheck what they are sending out.