First of all, if what you say is true, then the contract itself is invalid.

Of course, the most important thing is that you can produce conclusive evidence.

That's not surrender, it's termination of this contract.

And the insurance company should refund the premium you paid to you in full. You can contact the insurance company first, explain the situation and see their attitude. If not, you can file a lawsuit directly. As long as you can prove that the signature on it is signed by the agent. Then you are sure to win this lawsuit.