Turbo guarantee

I'm very disappointed with the service at Goldwagen. My husband purchased a new turbo for his car with all service stuff. Two months later the turbo broke. We called Goldwagen because part had a 12 months guarantee. Goldwagen send part in and told us in 2 or 3 weeks we would hear from them. We kept phoning we are told oh the pard only went up this week. The next week I phoned again was told the same thing. Eventually they told us that turbo place was closed for festive season. We waited again and the response we got was shocking we paid R7245. 00 for a new part with a 12 months guarantee but cost to fix the part would cost around R5500 how does this make sense. How can a brand new part with guarantee only last 2 months. This it ****************. I don't think this is fair.