My contract is from January 2005 and explicitly states
3(c) If you have a prepaid membership,24 Hour will not increase your Guaranteed Annual Renewal Amount on the front page of this Agreement, so long as you remain a member in good standing.
The only mention of 3% increases is for monthly dues, and can only be increased once per year.
3(g)states that a copy of the contract can be requested for a $10 fee.