Just look at the FAQ. They update it from time to time, so it’s worth it to check it regularly:
Can I get a refund on my phone pre-order?
Per our policy, we can not provide refund for orders that are in the pre-order status.
Now that we have placed the “Evergreen” batch order, your funds are locked into that order. We can’t refund those funds until the phone goes from “pre-order” to “shipping now” status. Once the phone (final, mass production build batch) pre-orders start shipping and we reach your order in the queue, we will refund the full amount you paid, unless you change your mind.