Sorry to hear that OP :/. I've shipped over 7 giant hauls to my sister's flexdelivery in Canada (China SAL) and havent encountered any problems. I didn't know Cssbuy even had a tax-free/shipping line - must be new! but I would have avoided it out of an abundance of caution. many people have warned private shipping lines to canada from ANY agent forbid branded items/often confiscate them. I think superbuy just removed its shipping line option to Canada (in the past year?) due to all the complaints.

CSS is one of the few (maybe only) agents allowing China post for large packages without defaulting to ems or DHL. I would recommend them if you want to use ems/China post.