Sinking more deeply into hot water, Atmos Energy acknowledged something that Dallas-area customers have been complaining about for months: that the system it uses to estimate monthly charges has problems, and that it intends to issue refunds.

Customers of the gas company have been complaining about soaring bills since January. According to CBS/DFW, more than 136 people have complained to the Dallas Better Business Bureau of abnormally large increases — with bills in some cases climbing from $50 a month to $600 a month.

In response to complaints, Atmos has either blamed the cold weather, or else promised to investigate and then never followed up.

The billing issue came up when the energy company made a presentation to the Dallas City Council on April 18 to talk about gas leaks in northwest Dallas that resulted in the death of a 12-year-old girl whose house exploded.

In its comments to the City Council, Atmos acknowledged that there were problems with the estimation system it used, and that it resulted in bills that were disproportionately too high.

This was a change from the company's previous defense of its system.

"Consumption last year vs. this year would be vastly different as the colder the temperature is outside, the harder the heating appliance must work to maintain the warmer temperature inside the home," Atmos told NBC DFW 5.

Atmos is not the only company that relies on estimates. In Texas, bills may be estimated, as long as an actual meter reading is taken at least every six months. Not having to send out meter readers every month saves money. Atmos claims that it never estimates more than two consecutive months, and that, if the estimate is higher than actual usage, customers get a credit the following bill.

The company told the Dallas City Council that moving forward, it won't use the estimation system in the winter, and pledged to issue refunds on bills.