The Supplier refuses to cancel and take back produ

I signed up with one of London School of Investment's (LSI Trader) broker, Mr Mobeen, for the software and was delivered to me in Decemeber 2014 but i have not opened it and the monthly instalments have been deducted from me since December 2014. As of this year, I've been having financial challenges with paying my instalments because of the financial burden which was unforeseen. So, I contacted the broker and explained myself as such and he told me to contact Robyn of which i did and she told me to just send an email so as to put it in writing and i did so on the 12 of March 2015 at 13:49 but i received no response until to date. I then contacted her again via phone when they debited me in April and she refused to talk with me but handed me over to another person who said to me according to them, once 7 days have passed you having the software, one cannot cancel but continue with it. I then explained myself again and mentioned that on their contract it states that one can cancel but must do so a month in advance and i also asked if that's the case, why then did she want me to send an email for cancellation. Please help because I haven't opened the product and I can't afford it.