Everyone starts the same when they sign up, they start as a Hack and progress through the tiers to Amateur, then Pro, and finally Master, based on how well they play. You were just promoted to Pro because your average dropped below a certain mark. This enabled you to buy 'exclusive' pro+ rated equipment. Using this equipment in a tournament that you registered in while you were still an amateur would be an unfair advantage because you still play under 'amateur' conditions for the remainder of that event. You'll just have to wait for the next month or week when that same type of tournament is offered. Or play the current one with your old clubs.