Don't rob your clients

I ordered 2 large pizzas as per the description on the apps menu. I then get 2 medium pizza and they telling me they will take it up with the restaurant. I got less than what I paid for. I further sent an email to their support team as instructed to they respond to the email I sent saying it's not the original email address I used but that's where they sending the emails, receipts to. So I don't know. I want a refund or the correct order LARGE PIZZAS DELIVERED