[JabbaPapa]

So surprising - Microsoft said that I should speak to Lenovo, playing Ping-Pong with a customer is obviously a very funny thing.

Any suggestions?

Microsoft are right, it's normally Lenovo's responsibility -- and I'm virtually certain it's a battery issue, not a Windows one. Given that you have paid $50 for zero outcome, I think you should make shouty noises at Lenovo for failing to discover the fact that there are problems -- from what I have read, it would appear that customer support at Lenovo is quite abysmal though

What you need is a new battery, notwithstanding these people's claims that there's nothing wrong with your current one. You cannot even be sure that they actually tested it properly.