KT said on Tuesday it will extend the cutoff date for eligible customers under its "customer reward program" to Jan. 31 from Jan. 13.

All customers using KT's wireless service as of Jan. 31 will receive the customer reward program from February.

KT will offer five programs: automatic provision of 100 GB of data to all customers for six months from Feb. 1; a six-month voucher for an OTT service from February, with a choice of Tving or Disney+; six months of benefits from popular membership partner brands, including free coffee, from February; two years of free cyber financial crime victim compensation insurance (Safety & Peace of Mind Insurance); and 50 percent additional data on top of basic data for customers using roaming services from March to August.

Hee-geun Kwon, head of KT's Marketing Innovation Division, said, "We changed the eligibility cutoff date to just before the program begins so that we can convey our gratitude without leaving anyone out to customers who trust and choose KT."

Hyun-seok Lee, head of KT's Customer Division, said, "We once again bow our heads and deeply apologise for causing concern to customers due to small-amount payments and security incidents." He added, "We will focus on strengthening our information security system and work to provide safer telecommunications services."