Write to Customer Support. I have cut and pasted their information about this from their help pages:
I purchased the standard version game. Can I upgrade to the Collector's Edition without losing my progress in the game?
Oftentimes, a standard version and Collector's Edition of a game will use the same saved information. However, this differs from game to game, and upgrading to some Collector's Editions may require you to start the game over.
Please note: We are unable to offer upgrades from a standard version game to a Collector's Edition that was purchased at a sale price.
If you've already purchased the standard version game and would like to get the Collector's Edition, please follow the steps below (not applicable to Collector's Editions purchased as part of a sale):
Purchase and download the Collector's Edition.
Contact Customer Support and we will offer you a refund for the standard version game. To help us find your order, please include the purchase date of the standard version game you wish to upgrade.
By purchasing and installing the Collector's Edition before we refund the original purchase, your player profile can often be saved, preventing you from starting again from the beginning. This differs depending on the game, and is not the case for all Collector's Editions.
It does say that they are unable to offer upgrades from a standard version game to a Collector's Edition that was purchased at a sale price. If you did purchase the game at a sale price, just write to them and explain that you bought the standard game in error, and I'm sure they will get it straightened out for you. Their Customer Support is very good.
Need batteries, can't find them. have a broken drill, have no idea how to fix it. 
