I have an OMRON E3 TENS machine, a relatively low cost beastie ($70?) about the size of a TV remote control that you should be able to buy online ( E4 and E3). I realise that she has an awful problem, but every little bit helps. TENS really does help (it is an external version of the stim), and is benign - it is used by pregnant women with lower back or abdominal pain.

Have you considered simply driving into the emergency department of the local hospital?

Do you have a district medical ombudsman or other independent official who you could submit a complaint to?

I know what back pain can do - grind you into the dust, and keeps on grinding. Tears are often insufficient: my support and best wishes to you both that you can get this resolved quickly, and satisfactorily in order that you can resume some normal semblence of life.

Good luck - if we can help, I'm sure you know you only have to ask, OK?