***** PNP ASAP

I placed an order on PNP ASAP with a total amount of R113, authorised the payment and placed my order, a few hours later I noticed money missing from my account to find that PNP amended the total on my order and took and additional R155 stating on the invoice that I bought x16 snow***** where as I had only ordered x4!!! No one called from the store, no one made me aware that they were taking more money out of my account and neither did they apologise, instead a lady from customer care called making excuses saying it was a system error and they cannot refund the money back into my account, they will add it to the PNP wallet and I can access it after 3-7 working days, this is *****! PNP has no right to deduct money from my account without consent