Since there's not much information in your post, bear in mind that email responses to retailers aren't fast on weekends, if you've sent the email in the last couple of days.
Other than that, I reccomend you:
Fax Laser's Edge a copy of your email invoice/etc and also the letter from the post office, so that they can check with the post office for confirmation/validation, etc.
Read this recent post of Drew's, with special refenence to points number 1) and 2), which I will quote here for convenience.
As Drew has said in his other recent posts, this makes sure that issues raised with stores are valid and lets them check up immediately on your specific issue and answer it here publicly (or directly and privately via email).Best of luck with your lost discs.
cheers,
scipio

