Coupon code doesn't work?

The website says to enter coupon code CYBERWEEKS21 to get discount.
As I click Redeem Code the price doesn’t change at all.
Whats going on? I guess the prices are already 30% lower?

It should show the original price as strikethrough and the discounted price below that if the code is already applied. Example:

If the price isn’t shown like that after entering the code, then you’re trying to apply it to a version that isn’t included in the sale.

Ah, the old “up to 50% off” a.k.a. “at most 50% off” a.k.a. “less than 50% off.” Guess I won’t be trying TGuitar after all.