What to do with harassing Text Messages from fake number?

I've been dealing with Harassing text messages the past year. I know it's my child's mom, but I cannot seem to prove it. She uses her regular phone number and several other fake phone numbers to send harassing text messages to me and my wife. I have contacted law enforcement, but no one takes you seriously. I mean I don't blame them when you have serial killers and sex offenders running the streets. Even when I confront her about it she plays innocent and says it's not her than 5 min later I receive a text message with a smiley face or a "LOL" I've even went to the County Sheriff's office and they pointed me back to my judge who signed our Child Custody Court order. & The only way to see my judge is to go back to court. I'm really exhausted with options. I've spent tons on lawyer fees for my Custody case, the text messages continue, and she is still harassing me. I would hate to drop another $5000 for a lawyer to go to cour