Kakao, which runs the KaKaoTalk messenger app, started handing out three emoji packages to its messenger users Thursday as a general compensation for a data center fire last October, but faced criticism that a free service it also offered transitioned into a paid subscription.

“To compensate all our users for the damage caused by the fire at SK C&C data center last year, we are going to hand out the ‘heart package’ which includes our three new emoticons,’ Kakao announced Thursday.

Last October, the fire broke out at one of Kakao’s data centers which caused a blackout in Kakao services. As a result, KakaoTalk and other related services experienced massive disruption, affecting nearly all sectors of South Korea, ranging from social networking and business to finance and transportation.

Of the three emojis provided by Kakao as its compensation package, only one of them is permanently free, while the other two are valid for 90 days.

Additionally, Kakao offered vouchers giving a month's free access to its Talk Drawer Plus data back-up service, for the first 3 million applicants in its first-come-first served draw.

However, Kakao’s compensation has drawn criticism, particularly of the Talk Drawer Plus voucher promotion which automatically charges its users the subscription fee after the voucher expires.

In response, an official from Kakao Co. explained that adding payment option is unavoidable for this voucher service, adding, “we are going to send notification messages to the recipients of the vouchers so that they can cancel the automatic pay bill function before their voucher expires.”