Apple Gift Card code not accepted: what to do
A rejected code almost always comes down to one of three causes. Go through them in order - in most cases the code is accepted on the second try.
Cause 1: account region
A Kazakhstan card is only redeemed on an Apple Account with the Kazakhstan region - Apple rejects cards from other regions, and no error message says so directly.
The country and region are visible in the account settings, in the payment section. If another country is set - we have a guide on changing the region to Kazakhstan.
Cause 2: a typo
In a code it is easy to mix up zero with the letter O and one with I. Rather than retyping it, copy the code with the button on your order page - the email links to it - and paste it into the App Store.
Cause 3: the code is already redeemed
Check the account balance: the first attempt may have gone through, with the error shown only on the retry. The balance is visible in the App Store under your name.
Nothing helped
Write to support: include your order number like AC-XXXXXX and a screenshot of the error. Every code reveal is logged on our side, so the investigation is quick, and we replace codes that do not work.