Every seller has their own policy, but generally if it’s your county your pretty much lost unless the sellers willing to reship but you’ll most likely have to cover the cost of the items + a portion of shipping. That’s if you order directly. If it’s via agent then nothing can be done

Edit: if it’s in China, it’s usually returned and they just reship

I had a package from her seized by Chinese customs (DHL) and she reshipped by EMS with no problems. I think their responsibility is to get it out of China for you but if your country seizes it that’s on you

Let's say I buy a product from Apple and customs in my country are seizing it. Do I get a refund from her or am I simply lost?
Also, what happens if Chinese costume bust my package?

TS Apple refund when customs size package