I see now. Well, you can either reduce the amount of the caloric surplus through reducing food intake or you can keep the same intake but do some cardio to burn some of the excess calories. Whatever way works better for you.
What surprises me is that you say you're getting far too quickly while on only 3100cals a day. How old are you? What's your activity level like outside of the gym? What kind of job do you do? Are you sure you're tracking calories precisely? And if so, have you ever had a thyroid checkup?