Huh, keep trying - I've dealt with CZ-USA customer service for years, and they are consistently the best I've ever dealt with. If you can't get through on Gun Smithing, try pressing two for Parts after you dial 1-800-955-4486. Let me know if that works - do remember, they are screamingly busy right now - I managed to get through yesterday to some higher ups, and the business is insane.
I actually never knew about the cheap CZ re-contoured bolt handle, good to know!