Bad workmanship/bad after service management

I bought a couch for 26k in total, after one year the couch started sagging. I phoned to complain the couch has been for repairs twice and I'm still bitterly unhappy with the quality of work. The saddest part of it all is the managers do not even look at their messages. The managers make broken promises. If a couch cost 26k you would expect the item to be of a decent quality. I'm extremely unhappy!!!!