[eenieMINI]

I read that slightly different. I read, you must/need to notify them of shipping error, give "a certain amount of time" for them to respond and then its yours. So sending a letter saying thanks for the gift is not quite the same.

Here's the way around it, though its not what I'd do personally, when you give that "certain amount of time" for a response you put the date as the date you write the note, give 24hrs from that date and send the letter the next day. The time period will have passed by the time they receive the notice and you're covered. There is no specific requirement of time but it seems clear to me at least that there is a requirement to notify and give time period to respond.