How Do I Retrieve Deleted Phone Number On My Sony Ericsson W300i?

If you atleast remember a part of the phone number, this might work.

1. Go to Messages >> Write New >> Text Message.
2. Press Continue.
3. Go to Contacts Look up >> More >> Unsaved Numbers.

Now, you'll see a list of unsaved numbers that were dialed from or to your phone. If you remember atleast a part of the deleted number, you can retrieve it.