how could I contact the seller to unlock my iphone 5s ?
Best answer by theartiszan
If you were not the original owner of the phone, your can not contact the original owner, and are not a t mobile customer, you will not be able to get it unlocked. Maybe the person who gifted it can reach the seller.
Here are the requirements to get an unlock code.
If you do not meet these requirements, you will need to buy an unlock from a company online that sells them.