Both email and phone, but for full transparency we actually prefer email since it keeps a full log of conversations with consumers for both parties to have. Our card has a number on the back of it and a few other in-app spots have our number on it.
Thanks this is good to know. I think many people prefer the immediacy of phone support when they are having a payment issue. I looked through your FAQ and didn't see any mention of support which is why I asked. Congrats on the launch!