You will lose those points at some point in time. Some of my losses that occur that way can take up to two hours to show up. The point loss is always -31. Since your internet connection isn’t working, you connect but when you cancel, it counts that as a defeat or abandoned match. I have ~6000 matches in arena right now with 107 losses. A bunch of my losses occurred that exact way.
Unless you have given your email address and DQ password to someone, you should not worry about someone playing under your profile mate.