Confirmed with customer that kitchen sink would not drain. Customer had clean out in basement for kitchen sink that we had used to drain clean previously. Opened clean out finding no standing water determining blockage is between clean out in basement and kitchen sink upstairs. Removed trap under kitchen sink and used cable clearing out food blockage. Customer has a backwards trap under sink and cast iron piping going into the wall. Provided estimate to replace drsin piping for kitchen sink customer declined work. Ran water verifying proper drainage. Filled sink multiple times and is draining properly. No warranty or guarantee on drain cleaning. Thank you for choosing CPI plumbing and heating.