How to get the subscription contract from a refund notification

[ToyboxZach1]

I have a subscription app, and I am subscribed to refunds on the orders. I was wondering how do you get the subscription contract id from the refund webhook call. 

There doesn't seem to be any listed way to get it, and we need to know which subscription contract it comes from to handle stuff on our server.

The only way I can see to connect a contract to an order is to look through all the orders that are associated with a contract, but we need to go the other way and find the contracts connected to the order.