Incorrect billing and poor service delivery

Unfortunately i should have written this review before, giving benefit of the doubt was clearly a mistake on my part. I was short delivered 1 item. when i phoned to query it, i was told i owe a substancial amount of money and that is why they did not dispatch this 1 medicine which is a co-payment item in my basket (the std co-payment is R44 but i am told i owe 10x the amount. When i refered the agent to my Tax Invoice i recieved it states clearly for the script nr in dispute that my tax invoice indicate clearly "pacient to pay R0.00". I requested the statement and the statement and the tax invoice qouting the exact same scripts number the statement and the Tax Invoice differs. Pharmacy Direct refuse to send the last item until i settle an amount owing which according to their tax invoice i owe nothing. Did i mention this order is for my mother who suffers with sefere depression and bi-polar disease, axciety and PTSD. Consumer protection act states a consumer must pay the amount stated on a tax invoice and the vendor is accountable for issing the tax invoice correctly. after a total of 1 hour on the phone over 2 sepereate conversations, nothing has been solved.