I WILL NOT PAY FOR IT!!!

I ordered a tablet two weeks ago, they first promised that this would be delivered to me within 5working days, which never happened, I had to make constant follow ups, thereafter they advised they would call me before they deliver and what happens? I am on leave the time they deliver at work, and they did not even call me before delivery! second time I advised them to deliver in the morning Friday as it was my year end function and we will be leaving at 11.30, I call the call centre at the courier service on: *** with *** THET TELL ME THAT MY PACKAGE WAS DELIVERED ON SATURDAY AND A PERSON NAMED KELVIN SIGNED FOR IT?????? No 1!!! they told me no one else would sign for my package why have they now allowed someone to do this??? No2 there is no person named Kelvin here????? I will not pay for that missing package you guys provide total and complete freaking horrible service!!! Someone better get back to me and explain this!!!!