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Very sorry to hear this, John - And, yes, it hardly gives you confidence while driving!
As it's happened twice I would insist on full refund of what you paid for them and then use the money towards more reliable ARB's.
If you got them through Awesome or similar, they'll refund you under warranty. Awesome were first rate in the case of my failed Koni FSD's from 2005 with 50k miles on them.