Today I went to the T-Mobile store to drop off my iPhone. The Customer Service didn't phone me yesterday and I didn't want to wait till after the weekend. Unfortunately, I have no way of informing them they don't need to phone me anymore, so I suspect they will still do it Monday.
The guy at the store looked at my -- complete -- copy of the receipt and asked what I brought last time. I pointed it out and he said I brought enough, the guy should have taken in my phone.
This time, the other guy filled in the forms, gave me a copy and told me they'll call me in about a week or two. Keeping my thumbs crossed. And fingers too.