South Korea ordered Samsung Electronics to conduct more security checks on the new batteries in its Galaxy Note 7 before putting the phones back on the market. The South Korean company launched a global recall of its latest flagship smartphone following customer complaints about the phone catching fire due to the battery overheating while charging.

According to the recall plan approved by the Korean Agency for Technology and Standards (KATS), Samsung’s battery supplier has to use an X-ray test for every lithium battery created for the Note 7 before shipping them to Samsung. Samsung will also have to conduct quality tests of its own on the newly arrived batteries.

“If there are 10 million units, all 10 million will be reviewed,” Nam Taek-joo, a KATS official told the Associated Press by phone Thursday.

The products safety agency has also asked Samsung to extend its refund period for customers who missed the Monday deadline for claiming them. Nam added that Samsung’s recall plan to remove “hazards” from the market was “insufficient.”

“We need more measures to actively inform consumers,” he added. “It appears that consumers are not active in seeking an exchange or a refund.”

Samsung announced that customers who missed the refund deadline can now get iPhones or other similar devices from the same carrier in exchange for the Note 7. This option is available till the end of September.

Samsung issued a worldwide recall of 2.4 million units of its Galaxy Note 7 and stopped sales a mere two weeks after the phone’s launch. The company has received 92 complaints of the phone overheating in the U.S. alone. There were also 26 reports of burns and 55 reports of damage to property.