Oxyhealth Tried to have a chamber repaired, they want to sell me a new one Santa Fe Springs, California

This is kind of a long story, but I'll try to keep it as short as I can.

We bought a used hyperbaric chamber for our 5 year old son with cerebral palsy. We have given him this type of treatment at a clinic with amazing results, so we decided to try to raise the funds to purchase one for our home, as it can be pretty expensive to have treatments at a clinic.

We bought the same kind of chamber that was used in the clinics which is a Vitaeris 320 made by OxyHealth. Before I even paid for the chamber, I tested it twice to make sure everything worked. As I live in Florida, we drove to Wisconsin to pick it up. before I even drove home I tested it a total of 5 times. and twice when I got home to Florida. 

We have had fundraisers the past 6 months to be able to purchase this. We paid a total of $7100 for the chamber and all the equipment that goes along with it, not mentioning the trouble we had getting a prescription for it as it is FDA regulated.

Once home, I inflated it once by itself, and once with me in it before our son got in just to make sure everything was working correctly.  As I was in it, the inside zipper split when it got to pressure (there is an inside and outside zipper). I rezipped it back up, and inflated it, and all seemed well until it got to full pressure. The main window (its kind of a
plastic window) blew open releasing all the pressure at once. Its effect on your ears is the reverse of going on an airplane, and the only way to get rid of it is to get down to pressure and allow the air to work its way out of your
ears. I think the relief valves failed causing the chamber to go beyond the rated 4 psi.

Needless to say, I was pretty upset about all this, but thought the only thing to do is send it to Oxyhealth in California to be repaired. I emailed the company to see where I would need to send it to, and the person that responded was pretty short with me, but gave me all the info I had asked for, along with a warning that "some chambers cannot be
repaired" this is understandable, but the condition this chamber is in, I didn't think twice about it. After 3 or 4 emails back and forth, (and with everytime him telling me that it needs to be reviewed and may not be repairable) I finally got a RMA number to send it in.

After spending $126.00 sending it in, and waiting 2 weeks after they had received it, I finally Emailed them and asked for an update on our chamber. He responded with "this chamber is not repairable, but we can sell you a new chamber for $7000 (just the chamber, not any other pieces) and they would keep my chamber" why on earth would they want to keep a non repairable chamber? Again, needless to say I was even more upset about this news after spending close to 6 months researching and raising money to buy one. I asked what specifically cannot be repaired, and what the chamber material is made of, along with if I request to have the chamber sent back to me if the price of $7000 is still valid. My feeling is our chamber can very well be fixed. 4 PSI is not much. They want to sell us a new chamber, fix our chamber
and sell it used. How do these companies get away with this?

After another 2 weeks go by, I Emailed them asking if they were just going to blow me off until I went away. They responded that the info I requested was proprietary and would not be released. So If I brought my car in to get fixed, and they came out and said that it is not repairable, I'm not supposed to ask why, or what cannot be fixed? I cannot express how I am feeling right now. Parents try to do whats right and good for their children, and then when something happens, you get yanked around by these types of companies. The ONLY reason I bought this chamber is because of the great condition it was in, and only after inflating it 5 times before I even brought it back to Florida.
These companies think we have money to throw around.

I just don't understand why they cannot answer my questions about why it can't be repaired, and why it takes them so long to get back to me. $7100 is alot of money to us, especially all the money it takes just to take care of a child with cerebral palsy. Update to come on how much they are going to charge me to send it back to me, and what kind of condition it is in.