Non cumulative group discount. How?

[Denes]

I can not create a non-cumulative discounts (for loyality customer groups).

Situation:

Some product are on sale with 5% discount.

I have loyal customer group (I made a group: customers/groups, then created for them 10% catalog price rule), they have 10% discount.
I'd like the customer from loyality group get 10% discount for the specials produts too (not 5% and not 15%). So I would like apply the higher discounts for the customers.

And... when log in a memeber of a loyality group, I don't want to show all products under the Specials („On sale”) menu!

 

PS 1.5.6.2, my test site: shop.flexa.hu

 

Have any idea to make this?

 

[Denes]

Nobody? Perhaps not understand what I wrote because of my bad english?

A little simplier: I try adjusting the discounts, but more kind of them cumulative. For example: Specific prices (Product/Price/Specific price - 5%) and cart rules discount (seasonal category discount 10%) are added together 5% + 10% ~ 15%. It is fault.

So I can't manage campaigns, I can not handle the loyalty discounts. Somebody help me please!

Edited May 18, 2014 by Denes (see edit history)