Pesel with rental contract under 3 months

Hello guys, I am a EU citizen that started working in Gdansk 2 weeks ago. I am currently living in a student residence for 2 months, meanwhile I'm looking for an apartment. I tried the other day to do the Pesel but the ladies there said that I cannot do the pesel with a contract under 3 months (mine is only 2). My company is asking for my pesel, how should I proceed?