remove discount price for particular size for every product

-- HikaShop version -- : HikaShop Business 3.2.1
-- Joomla version -- : 3.8.1
-- PHP version -- : 5.6.40
-- Browser(s) name and version -- : Chrome

Hello Support,
We have applied a coupon code in the hikashop(business package) when user purchase 10 or more than 10 products of any color and size. The coupon applies automatically when there are 10 or more products in the cart. we have set product with different variants, so that each product have size 2XL, XXL, XXL, XL, L, M etc and each size have different prices. It is working fine.

But how can we remove discount only for a particular size for every product. We want to remove discount price for 2XL for every product.

Can you please let us know the solution for it.

Thank you