Not everyone gets to see a check for $975 million with their name on it. But after a highly contentious divorce, Sue Ann Arnall is looking for more.

She rejected the check her ex-husband Harold Hamm sent her Monday, according to his attorneys.

Hamm agreed to pay the nearly $1 billion back in November. He's somewhat of a legend in the oil business, having built Continental Resources (CLR) from the ground up and led the development of North Dakota's Bakken oil field.

But Arnall, an economist and a lawyer who held executive positions in the company, has said she is entitled to more. She filed for an appeal, claiming that the fortune was due to both her work and his.

Arnall's attorney did not immediately respond to a request for comment.

Related: Oil tycoon is too broke for $1 billion divorce

The couple was married for 26 years, have two children and had no prenuptial agreement.

To make things even messier, Hamm himself filed for an appeal as well. He claims that with the dramatic drop in oil prices, his company's value has taken a hit, along with his wealth.

Despite writing the check, Hamm will move forward with his appeal, his attorney Craig Box said.