Redzircon

I apologize for this first post being a request, as I normally prefer to contribute before asking a forum for advice.

We have a 2010 Subaru Impreza XV with 136K.

We don't drive it hard, in fact my wife says I drive like an old man.

The gearbox and clutch inside it have just totally failed and I need to spend $3,000 on a refurbishment. The mechanic said when he drained the oil it was silvery. (I can add more detail on Monday)

Am I wrong in thinking Subaru gearbox should last much much longer? I would have expected 300,000km for such a durable brand. (The mechanic says we have another ~ 70,000km left on the clutch, which gives you an idea of how we drive it)

I was planning to buy another Subaru in the next year or so, but now...maybe not. Damn, as I love their AWD system, and the flat four.

• We tow a small trailer sometimes.
• We recently replaced the the thrust bearing. Could this have been installed incorrectly and placed the gearbox under pressure?
• Car was once hit from back left corner -- but up high.
• The car is driven on bitumen 99% of the time, and 1/2 of its use has been on freeways
  
  NB My wife said the towball was slightly loose, and so the trailer would jerk slightly as we started from a full stop. I wonder if this would stress the internal traction/clutch system.

Is there any point in writing to Subaru or making a fuss on social media?

Thanks