Okay, so to make this easy, this is the let me share the the letter I recently sent to Harrop Engieneering reagrdingt the front and rear lockers fitter to my 76 series crusier.
In saying that, I still think theyre a good locker. I......
I feel your pain mate. You must take this to fair trading.
I run 2 air lockers in my GQ and both have been fantastic (front is 9 years now) (rear is 4). but like you, I got them incase I need them and not because I do extreme offroading. Only time I have ever used both at once was on a recent high country trip in which overnight rain made things almost impossible to get out the next morning.
I had a similar issue with a DJi phantom 2. from day 1 i had major problems with it and because I lived in Victoria and purchased it from NSW they thought I would not bother with the problems. cut a long story short mate, after 6 months of issues and eventually a fatality flight, I spoke to fair trading and they told me how to go about getting it resolved. I ended up sending the retailer a letter of demand with all the right words (thanks to fair trading) and within 24 hours i got a full refund including all postage costs.
Never give up mate. if you believe you did nothing wrong, fight for it.
Interesting you said they accused youof being the cause. That alone would be reason enough for me to take it further.
whatever you do, I hope you solve the problem.