Incorrectly Billed by Playstation Network

I havent had a playstation now for over 4 months. Today I got billed for a playstation plus subscription for R749.00

It was on auto renew which was not disclosed before hand, neither was there any communication that the package will be automatically renewed.

this is uncalled for as now I do not have enough funds in my account to last me the month. please can the monies be refunded ASAP.