People's Gas outdated DANGEROUS gas lines!

People's Gas found a massive leak in THEIR plumbing under & in my building last winter-after my contacting 12+ times in the summer & fall, because of gas smells.
after 6 hours, with my maintenance crew & plumber, with 20 below zeros weather, they shut my gas off for repairs-for 3 DAYS!
i had 7 apartments, 13 tenants to put up in a hotel, and put in electric heaters, anti freeze pipes, etc.  they put ALL the gas pipes-from the street, thru my building-IN ABOUT 1957!  They gave me their complaint dept., and denied my claim!
is there an agency I can contact to force reimbursement!  They know unless it's $50,000, or someone died, I wouldn't hire an attorney for a claim this low!