It sounds like you're saying your wall is drywall, layer of foam, concrete.

Your drywall is adhered to the wall somehow which means you can use toggle bolts through it to hold your TV. Use a wall mount system that distributes the load by attaching to the wall through a wide rectangular frame (this is a common style), put a big toggle in each corner, and you'll be fine. If your mount is more of a point load, use the toggles to attach 2x4s or a 1'x4' rectangle of 3/4" plywood to the drywall (you could glue it for good measure) and bolt your mount to that. Drywall is a lot stronger that we give it credit for.

We were removing a large commercial duty flat panel monitor (metal case, heavy) held onto drywall with one of these mounts and toggle bolts in a space slated for demolition, and my tech forgot the tool to loosen the mount. Since the walls were coming down anyway, he figured he would just rip the monitor out of the wall. He was a hefty dude but those toggles and mount supported his full body weight plus the weight of the monitor and it took a lot of energetic yanking and shaking to get the drywall to break. When it did finally come down he took a good 2x3 section of wall with him.