I have this same issue, but its easily fixed. If you set the zoom level to like 50%, you'll see the rest of the screen and the buttons that you need to click in order to complete your purchase. Hope this helps.
Geez, how do you have so many credits? Newbie here wants to know.
You must have cookies enabled to play World Golf Tour as a registered user.
Please enable them before continuing.
Click here for instructions.
We've noticed that you may be using a popup blocker. If you're able to play the game without difficulty, please disregard this message. If you're having trouble, please turn off your popup blocker and try again.