And get a refurbished T440p with a quad core CPU that's fast and costs you a couple of hundred of euros. Replace parts when they break. No need to pay the premium for the new models.
That must have been a wonderfull f*up on the part of your service center.
Here where I live they would have to refund you the machine, if they weren't capable to repair it within 30 days (while under warranty, which I assume X1 Extreme was). The only manufacturer, whose service is able to achieve 30 days here is Apple ;).
With Lenovo, and previously IBM, I've had experience to have issues fixed NBD, even when I was retail customer.
Lenovo standard customer support sucks ass. Pay a little more and they route you to IBM support (at least in Canada). Those people are godly. Next business day, go to your home, fix whatever you want, accidental damage, whatever, all covered.