They overpaid by $10,000!
They were told however, that they won't be getting a huge refund.
"What the hell's happening? Something's fugazy about these two companies you know that?" Sal Mazarro said.
Something's fugazy all right.
Sal and Ruth Mazarro are furious at their utility companies which have been overcharging them for service since they moved in to their Lynbrook house back in 1970.
"I never think of checking the back of the bill. Who looks at that? I'm assuming they're going to charge me the right rate," Mazarro said.
But 41 years ago, the previous owner of their house rented to a tenant.
As a landlord, the house was classified as a commercial property and paid higher rates.
For decades, that classification never changed.
The Mazarros never read the fine print on the back of their bill.
The utilities insist their bills are perfectly clear.
"Give the money back, because you stole it," Nassau County Legislator Dave Denenberg said.
The Mazarros likely overpaid thousands, but won't see more than a fraction of their money back.
"National Grid will go back six years if you underpaid your bill and get your underpayments for the last six years. But they're saying if you overcharge, then when you catch them they'll only go back three months? That's ridiculous," Denenberg said.
"I just want them to be fair," Mazarro said.
Sal Mazarro says he doesn't even want the full refund.
If anything else, he hopes this becomes warning for others to read that fine print.