I, too, had a mystery charge also and was able to clear them up. I also had to cancel my credit card and get a new one; somehow my info fell into the wrong hands. Here's what I found out...
DRI*Elements (Digital River Inc.) is a billing company used by MANY software companies. Their contact information is:
Please call toll free in the USA @ 1 800-406-4966 between the hours of 8am to 7pm Monday to Friday, and 9am to 5pm Saturday to Sunday USA Central Time. Additionally, if calling outside of the USA, please call +49.221.31088.30
Hope this helps.