Hi there! I understand you’re trying to create a Cozytouch account, but you’re getting an error about the post number 71000 for Sarajevo, which you mentioned is correct. Let’s get this sorted out together.

First, just to clarify, when you say “post number,” you mean the postal code or zip code field, right? And are you entering it exactly as "71000" without any extra spaces or characters? Also, are you registering via the Cozytouch app on your Android device?

Meanwhile, here’s a step-by-step approach we can try to fix this:

1. Double-check the postal code field:
- Make sure the code is entered as "71000" with no extra spaces before or after.
- Confirm the country selection matches the city (Sarajevo, Bosnia and Herzegovina).

2. Verify your internet connection is stable, as connection issues can sometimes interfere with account creation.

3. Sometimes the app may have issues with specific regional postal codes. If the app is defaulting to another country or region, it may reject the postal code.

4. Try creating your account on the Cozytouch website instead of the app (if available) and see if the postal code is accepted there.

5. If issues persist, consider updating the Cozytouch app to the latest version (if you haven’t already), as some older versions had issues related to account creation and login.

Could you please try these and let me know if you’re still running into the same error? If yes, I’ll help you explore some more in-depth options or escalate the problem if needed.