mine get out of balance by as much as 150 grams each bloody week.!!!! from just road driving.

now i replaced all relevant components related to steering and front end parts(wheels beerings etc) and they still do it!!
was speaking to a mate who was about to buy a set of s/t and was warned off them by a tire dude who said there are balance problems due to alot of tires going out of shapes causing tires wobble.
this sounds exactly what im experiancing??!!!
what the hell should i do..?? demand a new set, or money back and get different tires cos no way am i putting up with 80 thou kays of wobble
thanks