Sprint re-activated my service without authorization - how can this be legal?

I called Sprint Monday May 4 to request putting my account on hold since I'm going abroad for a few months. I was told it was possible, and a few momemts later I got an email confirmation "Seasonal Standby CDMA plan was added to your account and the Connection Card Data Plan plan was removed".

Friday morning May 8 I got another email saying "3G Connection Card 5GB $59.99 plan was added to your account and the Seasonal Standby CDMA plan was removed".
After spending +30 minutes on the phone with Sprint I ended up cancelling my account - paying +$200 in penalty since it was ahead of contract end date. They told me that I cannot put my DataCard plan on hold (I only have that service - no phone), and that their CSR rep. made a mistake when putting it on hold, but that IT automatically activate accounts that are "incorrect" - like mine.

How can this be legal? Activate an account that has been put on hold/standby without the customers approval. Until today I was happy with their service - but I will never, ever use Sprint after this experience.