Sorry to hear. I'm not sure what to suggest except sell that piece of junk on eBay and buy an Oculus Rift. This is a real shame. I've owned three Vive's and have been a huge fan, traveled across the country demoing it to people. Probably got HTC several new sales. But the product quality seems to be degrading and lately the customer support is a complete joke.
Reading through this thread there definitely appears to be a systemic, heat-related defect with the headsets. So disappointed that HTC has refused to acknowledge the issue and make things right for their customers. If anyone wants to start a little class action chime in here.
Given the number of customers suffering these issues and the potential for PR sensitivity, reproducing, diagnosing and fixing this issue should be a major priority for Vive engineers. Excuses about limited availability of engineering hours and carefully controlling factors are just that - excuses. I expect they could point a hairdryer at one of the returned HMD's for 10 minutes and produce the errant behavior. I wouldn't be surprised if they already have reproduced it, and are just not admitting it.
I never had this issue on the original model headset, but am having it on the newer, revised, lighter version. I'd be interested in hearing if others have had the flickering problem on any of: the original, the lighter version and the just-released PRO version.
All I can suggest to all the customers who have been completely left holding the bag on this is to push back with your other vendors - pressure Amazon to take a return, call your credit card company and complain (ask if you have third party warantee extension maybe they'll cover a replacement), report HTC to the BBB, and most of all, share your experiences on social media. This company needs to be held responsible for it's wilfull ignorance and utter failure to live up to its warrantee responsibilities to its customers.