Possible to get a discount after 6 months?

Backstory we bought a new CRV-Hybrid . When we went to do the paperwork on Saturday night we signed on for the extended warranty at an add on of 2,500 dollars. Through Sunday I realized that we did not want the warranty. Monday my wife spoke to the finance manager who admitted that we can change the contract as he has not submitted the paperwork through. So she told him that she would like to just remove the extended warranty. Wife said he was really upset and was giving her an attitude. He removed the warranty no biggie right. Today I just happened to look over the new contract that was given and realized that not only did he remove the extended warranty but he added on an addition 2,000 to the sticker price. Is there anyway that I can possibly get that 2,000 back somehow? I know we should have double checked the paperwork before leaving and I’m kicking myself for it. It’s been 5 months. Do I have any chance to get any of it back?