Some negative stuff that is written here is completely justified. Hospitals here are simply bad for Thais and like someone said poor foreigners. I don't see why, for example, OP's wife's mum can't at least get some painkillers to help her out during this time.
The reason I got good "care" here is because I paid for it. Simple as that. Some mugs here keep harping about the same thing over and over how great Thai healthcare is here. Fortunately I learned early on that is is not. Far from it.
10 years ago during my first month in Bangkok when I met my ex wife, her 30 something year old friend got diagnosed with bone cancer. She worked at the same place as my wife - Siemens (BTS project). Germans do have great benefits and great insurance. Her insurance refused to pay (it was still Thai insurance)., so she was stuck at the government hospital (the famous hospital that everyone harps here about being so great) which I thought was something out of a horror movie.... literally. Four months later, she died.
I don't trust this place at all.