still no delivery

I ordered my products on the 7th of January 2020 and they responded immediately to say my order will be delivered in 4 working days today is the 21st January and still no delivery. I call them every day to track my order am told they will delivery tomorro, tommoro, tommor, and yesterday they even called me to confirm my address and today when i call them they say am order has been returned to their office. Am tired of this purthetic service, it's not like it's the first time that am ordering from them why is this now happening?????