If you opponent concedes it is not important at which game state. You will always get full points.
You will win full Elo points and if it is an Arena game you get full Arena points. I do not know what you mean by +11xp.
If you still have questions you should point out which game you are talking about and somebody will surely look into it and explain in more detail. I cannot do that now because I cannot know which game you meant.
Edit: I now see that you were talking about your game against dikkyboy. You won 11 Elo points in this game.
Please note that your opponent has an Elo of 134 at the moment. You have 138 points. I.e., you are almost equal on Elo points - you did not beat a player with a high Elo rating!
For Elo it does not matter if your oppenent has reached a higher Arena level as yours (your opponent has already reached Elite level). There is a separate Arena rating - you will see your points as soon as you reach Elite level yourself. Before that, Arena points are already calculated for you but you cannot see them.
And a final remark: At the time of resignation your oppenent had a winning chance of 0.00% (rounded to a hundreth of a percent) according to XG. Did you not notice that the pip race was 50:134 in your favor and you were already bearing off, while your opponent still needs 13 quarter crossings to even start bear off?