Origin double purchase, only one instance available

I bought an Origin copy of Sims 4 some time ago for my daughter. This week-end, I decided to buy a second copy for my son. However, after purchase, only one instance of the game is available, labeled "new" with about 70hrs playtime, and as one cannot log in twice using the same account, the whole operation was quite useless. So I successfully requested a refund, hoping from the bottom of my heart that my daughter's game will still be there when I get home to check. What is the correct Origin way to handle the above scenario? Do I have to create a second account for the 2nd instance of the game? Thx.