Loss of progress

Me and my family bought the pass to play Skyblock in Mineville server, we all had the nether pass as well and also the main account had the VIP pass. We got quite far into the game and had a LOT of stuff. We were playing one day and some people came on and the game started going glitchy... all of a sudden we were all disconnected from the world. Once we came back on the game we had a complete different island that wasn't ours and had none of our stuff. Our two minion miners are is the same place but wasn't near anything to work. We are very displeased because this was not our island and we have lost so much of over powered items and valuable things. We have lost all of our stuff and even lost a huge amount of sky bucks (nearly $1000000). If there is nothing that can be done about this then we would like a refund on our game because we have spent a lot of money on this game and have had most of it took off of us. The children are very upset.