This is the best place i know to ask.

My CE Geralt bust was broken (his pony tail had snapped off due to the sculpture being poorly packed in the box - not bubble wrapped or anything)

Its repairable as its a clean break right down the line of the scalp.

But after trying super glue (which just soaked into the plaster) i need to know what you all think will work instead?

the cost of sending back such a heavy and bulky item, coupled with the fact that there arent many left if any, is prohibitive to that idea.

You could try some model glue, like testor plastic cement. Not sure what the sculpture is made out of, so you would be a better judge if that would work or not.

I suppose but as its damaged it completely worthless as a collectible...

Also as the damage was due to bad packing the company should refund the postage if you use a couple of trading standards Acts in the email/letter If memory serves its plastercaste