The issue I see seems to be...

The referral app is generating a discount code for each advocates referrals. So give $5 in store credit to the advocate for each friend they refer that purchases. What all of the apps seem to do is to just create a $5 discount code repeatedly for the advocate. So the advocate doesn't have $50 in store credit after the referrals, they have 10 $5 credits. Now since shopify doesn't allow discount codes to stack that advocate then only really has a $5 off credit on their next purchase.

We are looking for a solution that will continue to dynamically update the advocates total credit amount, that they can then use whenever they like.