Infibeam.com — Late delivery

I made payment by cash on 29.06.09 in the bank.They received it on 01.07.09
The delivery promise was 2-4 business days.Today is 08.07.09 and 6 business days have passed.
When I contacted them they said i should inquire the Courier Company as they have already shipped it.
The delivery status has been changed to 'Completed' even when the I have not received the parcel.
They do not reply to the complaints mailed to them.
For every local book they have given the shipping time of 1-2 days.