Electric range not working properly

One way I have fixed things like this is to form new tabs out of metal parts. Have the new tabs bend down inside the back side of the plastic bezel piece where you use a good two part epoxy to glue the metal part in place.

For where the plastic tab may still be intact you can add a thinner metal piece and glue into place in the same manner to strengthen the remaining part.

I've had really the best luck using copper plate material for this because it is easy to work with and bends nice without cracking like aluminum does. Soft brass plate works too but is harder to work with. Use steel wool to clean away tarnish to allow the epoxy to stick better.

Turn the breaker off, pull the range out, and unplug it. Remove the access panel on the back (if there is one), and inspect the wiring where the cord attaches to the range. My guess is that you'll see one of the wires is disconnected, and/or one or more wires are charred/melted.

This is a fairly common problem, as I described in this answer. Depending on the amount of damage, the repair could range anywhere from simply replacing the cord, to replacing/rewiring the range.