Hi Sami,
Thank you for sharing your question. I understand you put in Microsoft gift cards worth 300 Turkish Lira, and your account's set to Turkey. But it's giving you a change your store region goof when you try to spend the money. I am here to help.
Microsoft gift cards only work in certain areas. Even if your account says Turkey, the Microsoft Store double-checks things like:
Your account's country in your Microsoft info. The address that goes with how you pay.
Where your computer is when you go to the store (IP address).
If those don't match up, or if Microsoft's having a hiccup on their end, you might get that error. Also, they've been cracking down on region stuff lately, so using a VPN or having the wrong address info can cause problems.
Here's what you can do
Check your region Go to account.microsoft.com and make sure your country/region says Turkey. Also, look in your device's settings under Time & Language > Language & Region.
Clean up the Microsoft Store Press the Windows key and R at the same time, type wsreset, and press Enter. That will wipe out old region info.
No VPNs allowed Don't use a VPN. Microsoft blocks stuff if they spot one.
Give it time If you just put in the gift card, it can take a day or three for Microsoft to get everything matched up for the Turkish store.
I hope this helps.
Best Regards,
Noel