Marking as gift does not exhonerate you from import duty - and it ain't a new trend - this has been being done for years.... Customs are like insurance companies - they know a shit load more about it than you or than you give them credit for

But if it was me, I'd ignore it and when someone comse knocking I'd say that you never gave any authority for payment to be made and that if you had been told when it came into the counrty that you'd have to pay XX you would have retunred the item, so not your fault they paid it and not your problem....

But thats just me, and it will probably land you in court