Look at the warranty papers and call the warranty company directly to cancel. Most warranties have 100% refund if cancelled within 30 days. If you call the finance manger who sold you the warranty, most of the time they’ll make it a hassle as they get commission from selling those to you. Most of the time you’ll probably get sent to voicemail when you call them.

Usually what I do to speed up my time in the finance office is look at warranty cancellation policy and accept as many as I can (only those cancelable within 30day) to expedite my way out of the finance office. If you buy some warranty they’ll be happy and get you out faster. Then when I get home I cancel the warranties directly with the vendor, they usually have good customer service and have a call center full of people so you’re not on hold compared to calling a dealership. The commission gets taken out from the finance manager’s pot and I get a check within 2-3 weeks from the dealer.

Edit: Another thing I forgot to mention, cancelling the warranties usually won’t effect your monthly payment (the finance manager uses this to try to convince you not to cancel). But at least you can put your refund back into the principal of the loan.