Searching new rear coil spring for my prius prime 2017

Hello

i am in QC, Canada. i often have adults in the backseat (carpooling between Quebec and Montreal about twice a month) and over the years i saw the back suspension wear out.

I ordered the full kit of rear suspension on performancetoyota(dot)ca (shock mounts, struts, insulators, springs)

it was the 26th june and 2 months later my order is still on hold because one of the springs is backordered from toyota canada. each time i ask for news they say the estimated time of arrival is 3 weeks. this morning they say `mid september` , but i doubt time since it`s the 3rd or 4th time.
they offer to send me the order as is but i would just have one spring it`s useless

Does that means that absolutely no 2017-2022 prius prime can get it`s suspension serviced in canada since at least 2 months ?
I absolutely want to get my parts before it gets to cold to DIY, and i want to do it all at once because an alignment is needed after the job.

part number is 48231-47360

i tried to check for alternatives on rockauto, KYB, etc but no alternative part seems to exist.
on moog`s website, the part finder does not works what a dumpster fire of a company

So is there another spring i can use for exemple from a matrix or whatever ? an harder / longer spring would be even better. (ps : i know about priusoffroad kit, but the price in CAD is horrendous plus they dont ship here) what would you do ?