Maybe it's different there but in the US, it's acceptable to go up the ladder.
Actually the reply says you can contact either the responsible agency in the US or directly a local lawyer.
If you win and are represented by an attorney you'll be awarded a reimbursement (Parteienentschädigung) that's supposed to cover your lawyer's cost. Since there's already a court ruling this seems quite likely.
Perhaps ask Frau Wittlin if she knows about organisations or individuals that provide legal services at reduced or no cost in cases such as yours before going up the hierarchical ladder. Her superior is probably Herr Loidl on this page .
& thank you very much for the advice, it's all very helpful.
Here the treaty in German: https://www.admin.ch/opc/de/classifi...index.html#fn1
The relevant authority according to said treaty is the «Office of Child Support Enforcement» part of the «Department of Health and Human Services», as specified in Titel IV-D «Social Security Act».
and specially https://www.acf.hhs.gov/css/parents/...national-cases
You can directly claim through them (or your states child support service), which then will forward the claim to Switzerland, which then will forward it to the canton, which then should act and get you the money.
Hope it helps. Good luck. If there is local research to be done, I'll happily do it for free (or a bottle of wine )
Thank you so very much🙏