XPS 15 9550 touchpad issue that Dell apparently can't fix

I've had my XPS15 since October, 2015.  The touchpad worked fine until 3 weeks ago when the mechanical click essentially stopped working--I can only get it to click by pushing very hard (10 times normal) along the very front edge.  It's physically broken, and it's not subtle.  It's essentially impossible to drag-and-drop, highlight text, or drag a scroll bar.

I called Dell and they had me ship it to Texas for repairs.  It came back 1 1/2 weeks later, but the touchpad still didn't work.  In fact, it was worse, as the front edge now sticks up 2-3 mm above the palmrest.  So, it doesn't work and it looks bad.

I called again and they had me ship it back to Texas.  It was returned yesterday, but the touchpad still doesn't click.  Per the paper inside the box, they replaced only the power supply and battery--I have no idea why.  (When I look online, it says they replaced the palmrest, but that apparently doesn't include the mechanical part of the touchpad.)

I called Dell again.  They want me to ship it back a third time.  Needless to say, I am losing faith.

Are there any other options?  I asked about taking it to a repair center local to me in Chicago, but they said there aren't any.  That's odd, as there are a bunch of them listed on the Dell service locator page.  At what point would it be reasonable to ask that the laptop be replaced?