I am in the same boat.  I also have a very large sum that didn’t confirm in time on Dec 8th (but did eventually confirm, just not in time for the invoice to be “paid”). Sent my first support request on Dec 13, followed up on the 19th, never heard anything except for an automatic reply confirmation once on the first email. Now, it has been 23 days since the transaction failed and they still have my sizable amount of bitcoin (more than $5k worth). I have yet to hear from them. I sent them a more angry message on the 30th to their email but overall I’ve been pretty patient and quiet for them having so much of my money for so long with no reply. Saying “it will be 1-3 days and don’t send us another email or we’ll reset your place in line” doesn’t cut it when weeks have been dragging by. I have also started pinging their social media pr representatives to deafening silence. 

 I’m getting close to involving legal representation.