Dont think you can close an account. I stopped playing in 2016 and contacted CS and asked them to close/finish my account. I even had a confirmation email to confirm this.
Then in November last year, I was bored and thought I'd 'play' golf and was browsing WGT and saw my avatar on a players friend list. Tried to log on but couldn't so I again contacted CS and explained, ok it took them 2 days to re-activate my account, but when they finally e-mailed me to confirm my account re-activation, everything was 'as I left it'.
Quite glad they didn't finish my account, so I assume they don't totally close an account!
But disapointed upon my return to find no Oakmont.