I just had my brake pads replaced n rotors turned today on my 2012 Malibu

On both wheels? I had that problem with the right wheel and it turned out that the rotor had not been turned correctly. A friend also had the problem right the moment he pulled out of the shop, they had used low quality pads. Once replaced for better pads and more money, the grinding stopped.

I had mid grade pads I'm taking bak Monday I didn't pay 150.00 to hear the same noise as before they didn't do something right

You have the right to receive good service when you pay for it. Meantime, try to go easy on the brake pedal and, if possible, don't drive the truck much until you Monday.

I,ve been in the business for over 30 years and I need to know what type of pads you installed? Were they semi-metallic, full metallic or Kevlar? Semi and full metallic pads are very hard compound and the cast iron rotor is comparatively soft. The usual break in period for new brakes is up to 500 miles but most of the noise should dissipate within 50 miles. You will also experience chatter, squeals and odors during this period which means nothing. Did you use a silicone brake lube at all the contact points in the caliper bridge and slide pins? Dry brakes will squeal a lot since a squeal is nothing more than a high pitch vibration.

Is it possible that someone installed one of the pads backwards?