Your question isn't entirely clear. You bought a vehicle "as is" but they gave you a warranty. Those two statements do not go together. There is either a warranty, or, the vehicle is AS IS. Its generally not both.
Was the transmission bad from the time of purchase? Is that the issue? It would be helpful if you made your question a little clearer.
If the warranty that you received covered the transmission, you reported a transmission problem during the warranty period and they are not fixing the transmission, then that may be a violation of the Magnuson Moss Warranty Act and the Unfair Trade Practices and Consumer Protection Law.
This response does not create an attorney-client relationship.
Ms. Roseman knows PA lemon law and is in your state. It is well worth your while to contact her or someone else knowledgeable in this area of law for a no or low fee consultation.