Autocare Time sensitive Factory Warranty Expiration Richardson Texas

I purchased a new vehicle just 6 months ago. Then a week ago, I received a serious looking letter "Request for Immediate Action - Time Sensitive Material Enclosed" "Warning $2000 fine, 5 years imprisonment, or both for any person interfering or obstructing with delivery of this letter." So I opened it and read "Time Sensitive - Please act now" no later than 12/14/2016. It claimed that my factory warranty was about to expire and needed to add coverage. I called the operator on the 13th to verify why my factory warranty would expire when I purchased the vehicle late May and I'm pretty sure I got up to 3 years coverage then. So every time I ask details on my queries, the conversation would shift smoothly to coverage package, getting my credit info, and other personal info. And she sounded pleasing. The next thing I know I agreed to pay $4k and gave out my payment details including security code. I even went out to the parking lot to see the actual mileage on the vehicle. She told me I would receive e-mail confirmation and that my billing authorization was through my voice stating her name Jese Butler. Two days have passed and I didn't receive any e-mail confirmation, and that's when I realized something was off. I recalled our conversation and realized the inconsistencies of data. I double checked the letter and it wasn't from the dealership I bought it, just a random company from Richardson and also searched the phone number reporting this as a ripoff. I changed credit card and was advised to never ever give out credit card info over the phone to any random company. Ever.