I had a similar terrible experience spending $10 to transfer my number on google voice. Got the whole "Uh oh. There was a problem" error. Waiting for support

I had a similar terrible experience spending $10 to transfer my number on google voice. Got the whole "Uh oh. There was a problem" error. Waiting for support like you, and then I found some obscure google group post that suggested my address on google wallet was wrong. After fixing that and waiting a day or so I finally made purchase successfully. Google checkout/wallet is less than good, combined with virtually non-existent support is a terrible combination.