Your last words were,,, not appropriate.
Most likely you have a connection problem and you are the one disconnecting from them.
PVP is not perfect and even I who have a very good connection right now have trouble sometimes.
If you join a game and someone sees your score, they can leave but you will most likely end up playing AI them anyway.
There are a lot of reasons this could be happening but 15 in a row suggests your connection is slow. I think you will know for sure if you try logging on another computer with different internet connection and playing.
Good Luck!