That actually happened to me just recently. I had 
won a cel off ebay and sent the money 
immediately. Then, after a week and a half, I 
emailed the seller to see if it had arrived yet. 
After no response I emailed her again...then 
again. Finally, I got a response after three 
emails and she said that the cel would be mailed 
out the next day. TWO weeks after that email, 
nothing. I emailed her three more times and she 
said she would look into it. After nearly six 
weeks, I got an email stating that the post 
office had held the item due to low postage. She 
re-sent the cel and it came on the seventh week. 
I guess my advice is, things happen. Don't start 
playing hardball until you feel it is absolutely 
necessary. Here's the cel I waited so damn long 
for: