I hope I don't get banned for this but I'll tell you this as a heads up. I heard that first process in refunding ingots is that you get banned from the game first. Some youtuber talked about it. His big spender friend got banned upon requesting for a refund. If you are willing to go through that hellish process for your 600 ingots then go for it.
With regards to the topic, in my knowledge there is still no confirmation on what they mean about deposit. So far all the questions have been ignored. Hope those ingots come back though 'cause there might be some rich people here with big * who might go for a lawsuit on that false adverti*t.