That is the reason they say the warranty runs concurrently with the factory warranty... because if you pay $2500 for it and then after 2 years, you want to sell the car and get the warranty cancelled/refunded, they are going to tell you that you used 2 years of the warranty, and will only be getting 3/5ths of the money back.
You said it has only been 4 weeks, so you should be getting your $2,500 back minus one month of coverage, which would be about $42, so you should be getting $2,458 or around there.
Lesson learned - ALWAYS ALWAYS ALWAYS read every contract put in front of you. I read all 5+ pages of my finance contract. The guy asking you to sign benefits when you don't read it, and when you sign your name, you take on a legal obligation. "I didn't read it" isn't something that will hold up in court, and trusting the salesman to be your advisor and look out for your best interests is like trusting a fox to guard the hen house.
It's great they are going to (mostly) sort this out for you - but lesson learned, k? Imagine you found out that you actually signed a lease and have to pay $20k at the end to keep the car - this kind of stuff happens!
Understanding contracts is a vital skill to have in life. Be thankful you didn't get burned bad in learning this lesson