Dell — warranty void

HERE IS MY STORY, i have a dell xps 17 as a exchange system from 3 years almost and still under complete and hard ware warranty for another year, any way about 20 days ago the screen start go plank so i call the dell tec, the did the trouble shooting and the send the tec to my house change the mother board, any way after he did that, he refuse to wait to run a test to see if the pc working or not, so what happened after he left the pc not working, so i call dell, the send another tec withe all kind of part to change almost every thing, he did that, he also try to test the pc, here we are the moment of truth, the pc never work again, the tec call dell from my house and tell them about this problem, the keep send the wrong part, no body listen for what he sad, any way the guy from dell he sad we going to send y exchange system, i sad ok .i ask him how many days take dell to approve me ?he sad two to three days, ok so good so far, but what happened later is a night mair.took them 11 day to tell me which kind of exchange iam going to get////plus 15 days for 2 Technician TO CHANG THE PART so is almost 26 days and my lap still not fix or change, HERE THE BIG THING THE OFFER MY Inspiron 17R i can not take that so i sad no i want same as my old xps or something 16 or 15 inch the tech from dell he get maid and told me the will call y later, any way later in thy same day some one from dell he call me and told me the can not do exchange for me, the will refund my many for thy warranty, and i should send my old pc to depo, to be fix for one time, after that, the have no more warranty for me, he was so load and angry, i told him, NO I WILL NOT take money back, he sad we will call y back to tell y or final xxxxxx now i do not know what to do or what to say (PLEASE SOME ONE TELL ME WHAT I SHOULD DO)THANKS