Pathetic Service - Goods Owed for Months

I have bought a lawnmower from Game. A Ryobi 1200w model. I had given this in Dec 2010 under warranty to be fixed. Mind you this was only a month old when it was defective. I was not contacted when could not be fixed and went in Feb to the store enquire. I dealt with Maria with manager Klaas. I was meant to be contacted in 4 weeks. Eventually i was told I would get a replacement and should wait a week for stock. It's now June ... I still don't have the lawnmower or a replacement. I went in today again after numerous visits and Klaas said there nothing any one can do and I can get an alternative .... How is this ethical business practice ... He kept blaming the new system installed. As a consumer I have waited 6 months with no service no talk of when I can get service and I was encouraged by to try staff to use hello Peter in this query. I have my credit note and all the information needed.

Why is this so difficult to resolve, I would even take a display model I just want the lawnmower to take care of my home.

Game Bel Airs- is the store I have been dealing with.