New iPhone calls problem :(

Hello,

I picked a new iPhone 5 32gb from your store yesterday and being happy to upgrade from my iPhone 4 i was so excited that its LTE enabled and etc.

Fact is i installed the phone from iPhone 4 backup and everything went very great except one thing I CANNOT get calls. I live in Helsinki Kallio area.

So i googled and it seems since LTE is data only the phone needs to switch to 3G to receive calls but maybe your LTE is congested it seems since the phone is not getting calls. It simply transfer people to voicemail.

Problem is people are calling me and the phone is not receiving or showing even a miss call, it simply throw people to voice mail.

My question is are u aware of this bug? The internet is full of stories from many operators around the world about it, im now wondering why i upgraded if the phone is gonna be 3G only and what is your advice? Am i to return the phone, is it the phone or your network? And yes i upgraded to ios 6.1.3 but it didn't help.

Should i change the sim card or what? This is frustrating that i call myself as demo on LTE and it just doesn't show am calling ...

P.s i turned LTE off and the phone receives calls, so is it the phone LTE chip or your Systems? And if you are aware please tell us what to do, cause now am stuck with 800€ phone that does same as my older 800€ phone!!!

Thank you,

Jad