It's a shame that one is treated this way. Please write a letter to your landlord/management stating what has happen and that you are requesting that this problem be solve completely and quickly. If no response, then file a complaint with the local HUD/FHA office. This is the responsibility of the landlord to resolve asap. Many landlords do not understand that they can be sued for the acts of other tenants. After filing the complaint, the landlord is barred by law from evicting you for filing a complaint. If need be ,seek a restraining order against the neighbor. HUD/FHA will intervene and investigate the complaint. If the investigation finds a violation, the landlord will be held accountable for damages/fines for failure to prohibit the harassment. Thank you for your service and good luck.