Our Game release is stuck in appeals with Apple over promo codes

My iOS game release has been stuck in an Apple appeal for some time now. Our game was initially rejected for “Guideline 3.1.1 - Business - Payments - In-App Purchase”. Apple had concerns that our promo codes (which offer discounts on IAP) were in violation.

I would like to hear from any of you who have knowledge about IAP promo codes. What was your approach? Did you achieve Apple approval?

Our approach is to define multiple Apple IAP product definitions with different prices. For example, we might define the following product ids: Product1, Product1_Discount1. These products have identical functionality at different prices. We allow the user to enter a promo code. We consult our backend to see if the promo code maps to a discounted product id. If it does we load the definition for the discounted product id. Otherwise, we load the definition for the normal product id.

Here are more details about our case

Thanks