... The only possibility that came into my mind is that they have plan to scam the full amount by let op wait and wait until gets bored and forget about the whole matter. This is a classic method used by many services who don't care about their reputation.
Sounds like the typical scam instant /exchanges like changelly and freewallet and other exchanges like HitBTC lol. But let's see they keep responding OP on their ANN, maybe it can be solved soon.