Can I force EX to get child for visitation?

I have custody of my child, my ex gets her every other weekend for 5 days (Fri-Tues). He has refused to get her on his weekends for the past 4 months. Is there anything I can do to FORCE him to get her? Would child support increase if I am keeping her 365 days verses him getting her NONE, whereas before it was calculated with him getting her every other weekend?

Since one of the components for calculating child support is the number of overnights, the amount of support would change if he is not exercising his overnights.