The TOMI DVD was NOT available in June 2009, only the downloads.
The DVD was not available for pre-order until March 2010.
The only way you would have received an additional invoice on March 13 is if you had placed an order for the DVD AT THAT TIME.
$16.90 sounds about right for shipping outside the USA but having 2 serial numbers only means that you purchased 2 copies of the downloadable version, (not necessarily the physical version).
However, if the invoice dated March 13 states that 2 DVD's were ordered, you are indeed entitled to 2 copies of the DVD.
Post your ticket number (one of the ones you should have received when e-mailing support) in
this thread and Telltale will look into it.
EDIT: It looks like you already posted in the other thread, so please disregard the last sentence of my post.