Goods stuck for 4 weeks

Hi, I bought hair from chaina and was couried to you within 3 days. It has been with you for 4 weeks now. My tracking number is ********** 18856 with FedEx. Fedex gave you my proof of payment and an invoice. But you have not returned to them. What could possibly go wrong with 3 pieces of hair. Please look into the matter, I don't understand why it would take this long.