Using dd is overwriting a part from a device and not the whole device?

Question

I have a problem In my USB stick, it's 32GB but it's showing me inside Gparted that it's only 2.84 GB, so what I did is that I used the following command;

am@sam:~$ sudo dd if=/dev/zero of=/dev/sdd
    dd: writing to '/dev/sdd': No space left on device
    5949721+0 records in
    5949720+0 records out
    3046256640 bytes (3.0 GB, 2.8 GiB) copied, 12.8159 s, 238 MB/s
    sam@sam:~$ 

But I still have the same problem.