Not Showing Up To Visits. Should We Take Away Visitation?

Ca
We have full legal/physical custody of a 4 year old. Bio mom has 3 visits/yr and has missed 2 of them every year for the last 3 years. She changes phone numbers constantly, we can never get ahold of her and it will be months between hearing anything from her. She has not completed the court-ordered parenting/domestic violence classes in 3 years, and she expressed that she has no intention of ever doing them she just wants to "see her son whenever she wants" but she is very flakey and barely sees him anyway.. She never even calls him. This is harming our son, and I want the court to consider taking away all visitation rights since she is not utilizing them and it is messing with our schedule. Would the court consider this if I have all of the documentation/supporting witnesses/etc.?