My CAM is double what the contract states, am I obligated to pay?

I leased office space at this retail center in January of 2007. Now in May, I get a bill for an additional 40%, which I have to pay as one lump sum. It looks like they underestimated the CAM to get me to sign the lease. Actually the reconciliation shows the expensed are twice what I paid, and they are not collecting all of it due to some agreement exclusions( which I don't understand). I want to ask for the expenses in years 2005 and 2006 to see if they based the CAM in my contract on those years. I would really appreciate any help?

Based on what you say here, you could file suit against them (or at least threaten to do so) in small claims court or in regular court; filing in small claims court is easier and requires no attorney...you could try to collect all of the costs and damages that you suffered due to their behavior... You may also report them to your state attorney general's office if you suspect widespread fraud on their part.