My Typecover stopped working a week or two ago. After finding that people were having no response from MS I bought a Brydge 12.3 keyboard for my Surface Pro 4.
In my search for an answer - before I found many others have the typecover problem - I took my Surface to a computer store and tested it. My typecover worked on their demo model, so it's not a typecover problem. Their demo typecover did not work on my Surface Pro 4.
The idea that MS will sell me a refurb Surface to fix a problem they have caused is laughable. Add to that I'm in Australia and we are not well supported by MS at all, and our exchange rate pushes the replacement cost way too high. I don't even know if they have a local replacement system as their phone help centre only responds to users with an annual assistance subscription.
What I've noticed now that I'm using the Surface with the bluetooth keyboard is that the battery runs down at race car speed. This was never a problem that I've been aware of since buying the unit early in 2016. So now I'm running some run-down checks to see exactly how fast it loses charge.
From what I read on this thread, the typecover problem and the battery drain problem are linked.