Some South Jersey gas customers were shocked by much higher than expected March bills.

South Jersey Gas truck (Facebook)

Customers whose bills are estimated were charged a higher amount because February was colder than normal and could have meant higher energy use spokesman Don Lockwood tells the South Jersey Times. An estimated bill, according to the utility's website, is "based on the average amount of gas used during the same period last year and previous month." An inaccuracy based on actual use is adjusted in the next bill.

The shock came when, according to SJG's website, "approximately 3 percent of our customers may have received lower than anticipated bills" in January. The bills were adjusted upward for the next bill sending customers to social media and customer service lines.

Many trying to call customer service were told there was a very long wait to speak to a representative. "Unable to get a live person on the phone @ SJGAS for 4 days, now busy signal all morning?? Received my bill and it was 10x higher then any bill I have ever received from you," posted Dianna Donohoe-Jakon on the South Jersey Gas Facebook page, who was promised a call from the utility in a response.

Others complained about a lack of a meter reading for several months and being locked out of their account on the SJG website. The utility says in a statement they have upgraded its Customer Information System (CIS) to improve service.

Affected customers will see a more detailed message regarding payment on their next bill. SJG offers a payment plan in the case of bills 25 percent higher than a customer's previous estimated bill.