A utility customer says she was hounded for months by National Grid after receiving a $30,000 natural gas bill in an apparent company billing glitch.

As News 12 has reported, National Grid has admitted to technical problems that have been generating erroneous bills for thousands of customers. The utility says it's attempting to "identify, escalate and resolve these issues?in a more expeditious manner."

Carol Sykes, of Patchogue, says she finally agreed to pay an extra $4,000 in $10 monthly payments in an effort to stop calls from National Grid. Sykes says it's still more than she believes she actually owes.

"I'm sure I'm not the only person this has happened to," she told News 12.

Though National Grid says it's improving its customer service, it was hit with an $8.9 million fine from the state Public Service Commission for not meeting expected levels of customer satisfaction.

National Grid says it's working to resolve disputed bills and adds it's exceeded its customer satisfaction rate targets this year.