Can you cancel options on a signed new car contract?

I bought a car on Monday and wanted a remote engine starter which they would install on Wednesday. I paid for the remote start in the price of the car. By Wednesday I didnt want it anymore and had to go bac anyway to install some options that i still did want. I told the service department not to install the remote starter. and then went into the dealership to get my refund.

My salesman was a 17 yr old intern who couldn't make any decisions and kept deferring to the sales manager who kept telling him to give me an excuse why it couldn't be done. finally i talked to the manager myself and he initially shouted at me telling me "YOU ARE NOT GONNA GET A REFUND" told me how the parts had been ordered and services were in progress, warranties had been assigned.

in the end i told him i had not taken delivery and i didnt want it anymore, i came to his dealership in good faith and gave him a good deal the other day. he said he would see what he could do but no guarantees. i waited around for a couple of hours and he refunded my money.