New brakes squeak AFTER I remove my foot from the brake pedal!

The OEM pads for your car should be semi-metallic. I don’t think the pad material has much to do with what you are experiencing. I have put ceramics on mine and no noise either. Have your mechanic inspect it again, you might have sticky brake cylinders or something else. Do the wheels get hot? Check both. Changing pads without real trouble shooting would get too expensive.