I recieved a delivery with water from Poland springs. I never ordered it. I called poland springs they knew nothing about it. I called a local grocery they didnt either know anything. What should I do with the water?

ב"ה Shalom Although, you were not required to return the water, you went through the trouble to contact Poland springs, which is an act of Kiddush Hashem, since it presents you as a trustworthy person. (שו"ע חו"מ סי' רס"ו:א) However, as you said, they knew nothing about it, so you may use the water since there is no one to return it to. The only other thing which you may do, though you are not required, is to maybe wait a few more days to see if the mystery delivery has somebody who may explain it. All the best חג כשר ושמח