Realm not replacing with the world I wanted only get error

Started my minecraft realm in the world setting " play on realms" went thru the payment stuff and when it loaded it didn't have the world I had gave me a new world and it's not letting me replace it with the world I want without it saying error I waited hours to do try again and the same problem 

If it cant be fix in a few days I should be able to get a refund if I can't use it for what I pay for