I guess it has a better or almost the same ranking as Wroclaw University of Economics
No, it is far lower in the ranking than Wroclaw. A whole different kettle of fish. Poznan however has a good reputation.
This gives a clue. Szczecin is so far down it isn't in the main list:
Remember though that rankings aren't everything - there are lots of factors that you should consider. Better to be happy somewhere less well known than miserable somewhere prestigious. Life's too short for that.
'Scuse the repeat posts, but I've got a bit of time to kill and had a look on the Poland-wide rankings of all institutions. The Wroclaw University of Economics is number 44 in Poland among all Higher Education establishments, the Zachodniopomorskie Business School is number 289, 24 places behind the Vocational Higher School of Cherishing of Health and Beauty in Poznan. The Poznan Higher School of Business is number 34.