So I got the free 1 month trial in my email, used it, and it expired this morning. I cancelled it early yesterday, and it told me that it will not automatically charge me for any further PS+ subscription. Then this morning, I get two emails. The first saying that $17.99 has been added to my wallet, the second saying that I purchased 3 months of Playstation Plus. The email clearly stated that if I cancelled it before the month was over, I would NOT be charged. What is going on with this!? I'm very frustrated, as I do not have this kind of money to spend right now.
You should call Sony Customer Support for a speedy response. You should also turn off the automatic funding option under Account Management too.