Exwife continues to call police for nothing. Ramifications?

Every single time I have visitation with my son, my ex-wife calls 3x a day or more to speak with him. That is perfectly fine, of course, but even my 5 year old sometimes goes "No, I don't want to speak to her" (so frequently) and understandably so. When this happens, she calls the police. They have visited my home again today and told us to inform my ex-wife that wasting their time is not a joke. I sent an email to her letting her know that she was making a fool out of herself and that a missed call is not some sign that her son is in danger. Is there anything I can do if this happens again as far as filing a report against her? Technically I'm sure she's incriminating herself by falsifying a police report (she had told them she hadn't heard anything for 4-5 days when in fact it had only been one). But is there anything I can do as not only this is confusing my son but also embarrassing me in front of my neighbors? Thanks for your help.