you should have spoken and been more firm with the agents.
you will be paying X amount of rent until it's fixed. if it's still not fixed within 30 days of that we will reduce again by X amount.
if your not happy with this then fix it or start legal proceedings against me.
There was no agency managing the property, my only contact was the Landlord, and believe me, I told him numerous times the about the problems.
Withholding rent in most scenarios works against you, we couldn't afford to move or be kicked out as we were planning our wedding last year, instead we've decided to do what we have done, and save for a house.