If your pharmacy has a policy that allows further discounts on promotional products, you need to configure the Stack Manual Discounts option. If this option is not configured when you apply a manual discount at the Till for an item on promotion, the discount will be taken from the retail price, not the promotional price.
From the Retail Till module:
1. Click the File menu and select 6. Preferences.
The Till Preferences window is displayed.
2. Click the Loyalty Configuration tab.
3. Check the Stack Manual Discounts checkbox.4. Click OK.
Now when manual discounts are applied at the Till for promotional items, the discount is taken from the Promotional price.