In general, the key principle on this issue is that the anyone should take the responsibilities for his/her own fault.
Customs risks and related costs of seller's country are seller's (HiModel) responsibilities;
Customs risks and related costs of buyer's country (destination country) are buyers responsibilities.
The detailed policies are all based on those above principles.
a. If the parcel was rejected/detained by destination country customs, or the package was returned because of insufficient or incorrect shipping address provided by the buyer, or the package was returned because of "nobody claim":
1). the original shipping cost if not refundable (as we already paid that cost to the courier);
2). the courier will charge a returning cost (as this is not their fault, and they charge for carrying the package from one place to another), and this returning freight must be paid by the buyer, and as this cost is calculated based on the standard rate from your country to China, so the returning cost will be much higher than the original freight (our rate is deeply discounted rate, also the standard rate from China to your country is lower)
3). if you want the returned package to be resent, then the resending freight should also be paid by the buyer.
4). if the package was detained by your customs, you should work with the courier or contact your customs office directly and see if they need any documents to get it released, and if your customs refuse to release the package, then the lost should be taken by the buyer.