Bad service at debonairs pizza Oxford Street East London

I sent someone to buy me a pizza at debonairs pizza Oxford Street and it was not the first time they gave me a dry pizza with no toppings it was burnt I could not even finish eating it when I called them to complain they said I should return it and I had no means to return it back I was so hurt and disappointed I bought 2 small triple deckers and I'd like to be refunded.