Stored Credits, Micro Transactions, and Payment Processors?

I wanted to use a micro transaction model but want avoid proportionally large transaction fees by selling bundles of say 300 Credits. However, Paddle.com says stored credit ("Virtual currency or stored value, including but not limited to store credit, gift cards, vouchers") is not an allowable product.

Is there a payment processor that allows stored credit, or is there a better way around it, such as a subscription with usage limits?