Display price before the discount - line through

-- HikaShop version -- : 2.6.1
-- Joomla version -- : 3.4.8

Hello,

I'm having a bit of trouble with the display of the discount when using "display price before the discount is applied". I modified PRICE_DISCOUNT_END=" Off Sale: " which give the the langues I want of "XX% Off sale: $XX.XX each"
but when I active the Display price before discount it removes the XX% and puts a line through my modified PRICE_DISCOUNT_END= .

When I use "display discount" I get the attached screenshot 1

when I use "display price before discount is applied" I get the attached screenshot 2

I would like it to display as below when "Display the price before discount is applied" is activated.

$18.49
40% off sale: $11.09 each

I can give you back end access to the website if you need, but I really need some help on this one!

Thank you,

Thank you Nicolas for pointing me in the right direction, but I need a little more help.

I've got the discount to display correctly on the product page (see screenshot 5)

but I don't want to the discount to display in the item line of the checkout (see screenshot 6) I just want the unit price (e.g. $11.09) and the total price (e.g. $22.19) to display with out "-40% off sale".

I believe this can be done in the view, checkout/listing_price, but am unsure of the proper PHP to remove and replace to stop the display of the discount in the checkout only.