Doors were locked at Sara's Pharmacy and Gift Corner in Mission Friday afternoon.
A note posted on the door claimed a family emergency closed the store.
Pharmacy owner Sara Garza and pharmacy technician Valerie Flores stand accused of federal health care fraud.
The two allegedly schemed health care companies out $500,000.
"I've known these people for about 17 years, and I know that that is totally untrue, said customer Nancy Cordova.
It is absurd, and I mean they're so honest, and she's one of the few pharmacists that I know that is not only honest, but she cares about all her patients."
Court records allege Garza and Flores submitted false claims for prescription medicines that were never dispensed.
The records allege some Medicaid claims were for medicines used to treat health problems patients never had.
Garza and Flores are also accused of forging doctors' and patients' signatures.
Cordova claimed Medicaid fraud focus should switch to bigger businesses.
According to health care fraud defense attorney Eric Reed, mom and pop shops like Sara's Pharmacy are an easy target for authorities.
You have pharmacies and dental clinics that are very small, and it's very difficult for them to defend themselves against the charges, said attorney Eric Reed.
Reed has defended several people accused of health care fraud in the Rio Grande Valley.
He said a simple allegation can cancel one's ability to provide Medicaid services, a big blow to many valley businesses dependent on Medicaid money.
"And often times these small entities, particularly the ones that operate in the valley, have their business based on up to 90-percent plus Medicaid patients, said Reed.
Reed told Action 4 News authorities are concentrating efforts on the valley.
"Due to the large number of Medicaid recipients, people who are eligible for Medicaid in the area and the large number of service providers serving the Medicaid community, said Reed.
Reed said he urges those falsely accused to fight every allegation.
"They need to be vigorously examined and challenged so that the government is held to prove every aspect of their case, said Reed.
Because there is often more to the story than what has been developed by the government during their side of the investigation."
Both the pharmacy owner and her technician were also indicted on charges of conspiring to defraud different health care companies.
In total, there are 15 counts against the two.
Each carries a punishment of up to ten years in prison and up to a $250,000 fine.