Poor or No reception

Hi all,

I need help with my IPHONE 5. Just bought it 1 month ago and on a daily basis, when I go to a place where the reception is not very good (for the iphone 5 because my iphone 4 will display an excellent coverage) the signal disappears and NO SERVICE is displayed. It takes ages to find the signal again and sometimes I have to power off and on again to get the coverage back.... i think this is quite ridiculous...

I have read many tricks on different forums but they only seem to work on that particular moment and does not fix the issue...

Can anyone help? I would really appreciate!

Thanks a lot