Wow, Polish invasion on PrepaidGSM, witajcie!
I suppose you don't need any user name and password (like with Wind), just use the APN
internet.tele2.se, put the
AT+CGDCONT=1,"IP","internet.tele2.se" string in the connection properties,
*99***1# (or *99#) as dialing number and it should work.
P.S. When I wrote that Swedish was easy for you I didn't notice the Polish flag, for some strange reason I thought you were Austrian... I think I need to go to the optician!