Your "Promotions" page says:

HikaShop is an eCommerce solution for Joomla. It enables you to manage the shop's content, handle advanced prices conduct, heavily personalize store by providing an easy interface to customize. Visit HikaShop
20%
Off for all HikaShop products
Code: smartaddons_20

But when I go to the HikaShop site I notice that they DO NOT apply the coupon to ALL products. They apply only to "Essential" and "Business" version, but NOT to "Multi-Vendor".

If you have agreement with them to give discount to ALL products then you need to contact them and make sure their system applies the discount to ALL products.

If they only give discount for 2 of their products, then please change the description in your "Promotions" section to show this correctly.

Thank you.