I have a great deal of sympathy for your plight. If you do as they suggest, you could invalidate your warranty and then where would you be. I think you have been treated very badly, but this seems to be par for the course, nowadays. I think you should write a formal letter of complaint and insist that they sort out your problems - on-site.
By the way, what did they give you by way of support CDs. Was there and operating system pre-installed and can you get this back if you have problems?