By default our system always ships your orders with the fastest shipping method available for that country and if two services have the same delivery time, we choose the cheaper one.
So if you choose “default shipping”, you want to use Premium Special Line, but only Special Line.
If you want to use Premium Special Line of all the order shipping in countries where this service is available click on the Personal Account > Settings Tab and under Shipping Plan select Premium Special Line, then click Update.
If you want to change the shipping method to a single order you can visit your Cart search for the order and before paying, change the shipping method.
Notice that this is not available if you’re using the eWallet