Clicks not canceling online order made 5 minutes before, certainly a *****!

I have done a purchase online and phone to cancel 5 minutes later when I realised that I had wrongly chosen for the order to be delivered at home (with a R60 charge) instead of collecting at the shop. When I phoned Customercare, I was told that I could not cancel the order. I do not think this is in line with consumer rights! Moreover the customercare agent was very unhelpful. I will bring it further, unless Clicks reviews this approach promptly