Why are my international text messages not coming back properly on my Z10?

Please help.
I've just got a BlackBerry Z10 and the only problem is sending text messages to international number format (for Croatia, country I'm using my phone in at the moment: +385 xx xxxxxxx). Any text or phone call I receive is in that format and only if a number is placed in contacts like that my phone will recognise it as a contact. However, if I format the number I text like 00 385 xx xxxxxxx instead +385 xx xxxxxxx, message will be sent with no problem but reply will come from a number formatted as +385 xx xxxxxxx and will not be in any way connected to my message/potential conversation (also if I send a text to a number format +385 xx xxxxxxx it will not send, it will be marked with a red x and will write "congestion"). I've set the smart dialing to "unknown" so it shouldn't have anything to do with this problem.
Thank you for helping me.

Switch the smart dialing to Croatia if you are in Croatia?
Make sure the national number length is correct.
Or if you really want to add the number to the contact you already have and that should thread it.
But try changing your smart dialing first then reboot and see what happens

Posted via CB10 from my Z30