Your account has been deactivated - It has $100 Giftcard balance :(

Purchased gift cards from Costco using my own credit card
Redeemed to my own account
Made a BestBuy purchase on DoorDash using these funds
Purchase successfully delivered

A day later account deactivated. It still has about $100 leftover balance

What Terms of Service did I violate? Customer service seems hopeless. What next?

https://preview.redd.it/m21rk07tzizf1.png?width=853&format=png&auto=webp&s=6a8ec1ce9f3a07d3cf2dca0bb1ed7d04dc187768