I have been complaining to the landlord giving 311 notices since Jan. after I was awaken 2 am by stomping and getting cussed at because I complained about excessive stomping, it is being done deliberately and the lady upstairs is crazy... Landlord has spoken to her and to no avail. My lease ends in August, What happens if I decide to with hold rent until I find something by Aug. I don't think I should be paying over $1000 for a small 1 bedroom apt that is so noisy with a neighbor who bangs on purpose.

You can't withhold rent money and continue to stay in the apartment, it can be considered theft of services. If you are fed up tell your LL you plan to break your lease, he will likely keep your deposit and may also sue you in small claims for any rent money he misses out between now and August. 311 notice means different things to different industries,what do you mean? Start calling the police and demand that they respond.