Here's a suggestion - when a player reaches the required points to advance to the next level - stop increasing the target!
Example:
I was on 23560 as 'pro' told I need 25515 to advance to 'tour pro'. Fair enough. However, get to:
25638 - the target has now shifted to 27715! This has now happened around 3 times. Reaching the target, only to see it changed and out of reach.
Hardly encouraging players to continue.