thanks for your question
If the assessment is through the CSA then you will need to contact them to inform them that your income has changed and ask that you are reassesed
As for the texts that are being received these need to be reported to the police as harassment.
I would also suggest that unless it is required for any reason that the numbers that are causing problems are blocked from your financee's phone and reported as nuicense numbers to her mobile telephone provider
As the assessment is through the CSA it is really nothing to do with your ex and her family and it is for you and the CSA to deal with things, not for her to contact and harass you and your family
I hope that helps
please let me know if there is anything else I can assist with before you accept and are in a position to leave a positive rating