the same thing had happend to me about 12 months ago but all i was told was i had miss used the car to cause it to tear the sway bar out. and did not help at all.. but to make things worse i had purchased a front swaybar from whitline and it would not fit properly and when i spoke to whitline they then told me that it was not fitted properly and i should change my mechanic.
i was not happy with them i then modified the sway bar and things are now good. i use 3mm steel to reinforce to the rear sway bar..