[Crash] Unable to buy RP

I have the mac client, so im unsure if this is a universal problem or not.

When i go to buy RP, first it takes 1-2 minutes for the credit card screen to load, but this has always been the case.

When the window finally loads, a previously saved CC is there. I click the drop down menu to select a new CC, and right when i click on select a new CC or whatever that box says, the entire client completely crashes. This happened to me 3 times yesterday, and just now when i tried to do it again.