Short Sale Holdover Issue

[Mahboob Memon]

short sale holdover was served notice of vacate/quit last month dead line is 01/31/18. I called him to get keys we fixed an appointment for delivering keys which I did not reach in time and he left with out giving me keys when I called him he said go to talk to the real estate agent and agent says go to the seller so today I went to see the house found a notice of Gas Interuption in the mail box from National Grid(stated that they have not been able to identify a responsible party at this location if they will not hear immediately from a responsible party at this location the gas service will be interrupted) It look like the house is vacate but not delivered keys yet and no phone replies from the seller shall I change the locks with out keys? as it is getting very cold and could cause water pipes get freezes and burst.