Reimbursement

My kitchen sink clogged up and I called the plumber to come and fix it. They reason I called the plumber was becuase back in November when my bathroom tub clogged up, the landlord advised me to call a plumber. Therefore, I called the plumber to fix my sink. The plumbers had to replace the pipes under the sink becuase they purst, due to being old.
Now the landlord does not want to reimburse me because he wants the original pipes that were removed. So, to make matters worse, the downstrairs apartment got a leak on thier bedroom ceiling which is right under my kitchen. The landlord is saying it was MY plumbers fault for the further damage and will not reimburse me for the kitchen sink and said I am lucky he is not charging me for the further damage. Please help, I can not afford to loose the $400 to fix the kitchen sink. Thank you.