Sears Home Warranty Horrible, Service- Doesn't guarentee the warranty Internet

I have a Kenmore diswasher for a little over a year.  It broke again last night for the 7th time.  I have called and made a service call (it is going to take 2 weeks for them to come look at it) They have replaced every part and now we have cycled around to one of the first breakdowns.  They will not let me speak to a supervisor or someone who can tell me anything other than wait for the service technecian to diagnose the problem.  So at what point does common sense pop up and say that maybe the dishwasher needs to be replaced?

I am so angry and frustrated with this group.  They are never helpful and always pushing things off on the service technician to turn in paperwork for review. How many breaks on a year old dishwasher does it take?