monami555, got your message - sorry for a delay with reply.
unfortunately i was not able to resolve my problem successfully and time to get internet running was very critical for me.
As a result - i decided to save time rather than trying to get this *** working and properly activated.
My advise to anyone who does temporary work/etc in Germany.
Do not try to save few cents/pennies
go to
nearest SATURN shop
buy O2 modem and DataPlan SIM, and
register it over there, and
top up the credit you need at the same time !!! They might ask your passport, just as a proof of ID.
then have a pint somewhere
get to your temporary home and by then it's all will be working properly.
Note: this is not the cheapest solution, but IF you prefer an alternative then be ready to spend ages on this forum asking people "aaaaa, please help!!"
Note: be careful trying to get SIM from ordinary O2 shop. Depending on area and your language skills the seller can give you incorrect SIM card and you'll spend ages arguing with them or with o2 prepaid customer service what's wrong. The problem is that many of small shops have 99 % of phone or tablet customers and never dealt with modems, etc.