Two men who owned a Cartersville pain clinic that illegally distributed mass amounts of Oxycodone, were sentenced to 15 years each in federal prison Thursday.

Jason Cole Votrobek, 30, of Vero Beach Fla. and Roland Rafael Castellanos, 34, of Hollywood, Fla. were convicted in March on charges of federal drug and money laundering as a result of their involvement in a pill mill prescription drug operation out of the pain clinic they owned, Atlanta Medical Group, according to the U.S. Attorney’s office.

Votrobek was acquitted of similar charges in Florida.

“Pain clinics prey on so-called patients who are addicted to opiates,” said Harry S. Sommers, of the DEA in a press release.

According to the U.S. Attorney’s Office:

The two worked with a group of three other people — Jesse Violante, 35, of Vero Beach, Fla. financed and operated the clinic, Tara Atkins, 36, of Cartersville acted as the office manager and Dr. James Chapman, 64, of Macon was the primary physician — to inappropriately prescribe excessive amounts of Oxycodone to as many patients as possible, many of whom are addicts from surrounding states.

Chapman, who was frequently intoxicated according to the report, signed prescriptions that were often filled out by Atkins to maximize the distribution of the drug. The U. S. Attorney’s office reported the clinic was in the top 15 purchasers of Oxycodone in the country in 2011.

The operation grossed millions of dollars.

“Some of the doctors who dispense these addictive analgesics often operate under the guise of a stethoscope and a white coat, when in actuality they are nothing more than drug traffickers,” Sommers said in the release.

Violante and Atkins pleaded guilty on related charges and Chapman is awaiting trial.