U and TAM

I received a text message from my Czech friends who are currently on holiday which stated: Nasli jsme tu internet, ale u musime jit zas zpatky.

My question is: does the 'u' which I am assuming to be the genitive preposition meaning at, near etc, have the same meaning as 'tam' here? I understood the text as saying, We have found internet here, but we must go back there again.

Thanks for your help

 

"Nasli jsme tu internet, ale u musime jit zas zpatky."


I guess its typo of "už"(already)


http://slovnik.seznam.cz/?q=už&lang=cz_en

 

Thanks Kibicz, so I was trying to reinvent Czech grammar

 

I guess it is "feature" of one of phones rather then typo