Extra Space Storage Forced to pay for insurance that provides inadequate coverage Egg Harbor Twp, Nationwide

I rent 3 units from this Extra Space Storage location in Egg Harbor Twp. NJ.  On May 23, 2011, I had discovered many of my items were soaking wet due to a leak in the roof. I was given the phone number to file a claim for damages. I filed a claim and detailed all the items that were damages. The roof was leaking due to inadequate maintenance on behalf of Extra Space Storage.
About 2 weeks later I find out that I would only be compensated for the depreciated value of my items and not the replacement cost. 
This wouldn't be so bad if the damage was caused by an Act of Nature but it was due to negligence on the part of Extra Space Storage. Also, the fact I am required to carry and pay for this insurance, I feel I should be given better protection for damages incurred due to their negligence. 
The current replacement costs exceeded the value of my insurance though I feel I should have been compensated up to the value of the insurance I paid for since it was due to Extra Space's negligence and not an act of nature. 
Also, why am I paying for insurance that isn't going to give me replacement value of my property in the event of their negligence?  I think its a sham that I should take such a great loss due to their negligence and get stiffed for huge depreciation. The very least a good company would due is offer me the replacement cost of my items up the amount of coverage I paid for. 
I would not recommend this company to anyone since if you property is damaged due to their negligence they don't think they have to give you replacement value.