Whirlpool — Defect in washing machine

I had bought an automatic Washing Machine, Model Splash 9855, Chasis No: 1MB[protected], on 15th Feb 2009 from Home Care, 111 Sector 4, Vaishali, GZB, vide Bill No: 435. Since that day, there have been 4 service calls for the same issue. Every fortnight, the water is clogged at the outlet pipe and does not get drained properly. I have given calls to service helpline and everytime the engineer had to come and open the rear side of the machine and drain out the water. I have another automatic machine which does not have this issue. So I feel this is a manufacturing defect as this is a brand new machine. Please assist me in this regard as I do not feel calling an engineer every week for same issue will help.