bad service in terms of house maintenance

I moved in April, the house wasn't in a good state and more things broke. The hot water is brown and I reported on April. Telling them my body is getting a reaction from the water they never bothered to fix everything I reported. Decided not to pay because I am not happy with the place and I put in a notice 2 month's ago and they sent me a letter that was drafted on the 8th July telling to Pay and evacuate the apartment on the 16th July I only received the letter today which means I should evacuate the apartment tomorrow. They've also mentioned that they will take me to the lawyer's n blacklist me.