Having this problem right now. Deposited a moderate number of XRP from Kraken into Bithumb about 8 hours ago and it never arrived. I had a friend do the same from Binance and it showed up right on time. When viewing the blockchain entries for the transaction IDs, they both are correct, so Im not sure its attributable to an incorrect tag entry.
I have filed three support tickets (two properly in Korean) with no reply yet despite the entire business day passing in Korea. Its worth noting their phone support cannot actually render account-level support, so its basically useless. Theyll tell you to file an inquiry ticket.