Texas Christain Care Sleep Center will not replace CPAP machine Corpus Christi, Texas

I was diagnosed with sleep apnea two years ago. My CPAP machine quit working. It is a medical necessity. I took the machine back to the sleep center for repairs. They said the machine is out of warranty. They want to charge me to fix it. I have full insurance.  In the mean time I am without my machine at night. I have made calls to the center about the replacement. They have not called me back. They take your money for sleep studies but you can get no help when you need supplies. In the mean time I am sleeping without oxygen at night. My medical condition causes me to stop breathing at night and causes high blood pressure and other medical problems in the future.  I do not recommend this sleep center it is a rip-off.