If I exchange a product that I used a coupon on, will the coupon apply to the new product?
Your coupon applies only to the original purchase amount. It does not apply again if you exchange for a product and pay the difference.
The coupon only applies to the original purchase amount. So, for example, if you scored a 20% discount on your original order, you won't score that 20% off again if you're exchanging and need to pay the difference.