I had the same thing happen, except it wasn't a phone shop. I was puzzled as to why it allowed me to place it in the cart, then not select a date. It was actually Lizdreamz reply that helped me figure it out - it's that dang 3-day window!! I guess we just need to wait until the calender shows days that we can do the shop & log back then and place in cart & apply then. (I never went back to try, so I'm assuming that's what I should have done)