Dis-Chem Pharmacies - Shocking service by staff at dischem benmore

Dischem Benmore has dished out to me what I consider to be unethical, unprofessional, and disgraceful treament, as follows:
I am on a whole list of Chronic Meds paid for by PMB. One of the meds - Venlor, has a co-payment of R192.49 per month, and history shows (to me anyhow), that I have NEVER been supplied with this med until I have paid in full for it.
However, during last year sometime Dischem began trying to charge me double each time I went to collect me script of 30 Venlor tabs for the month. I took it up with one of the pharmacists who was there then (Ross someone), but he never came back back to me. I have taken it up with supervisors, till operators, another (female)pharmacist (Ancha?), but she never came back to me, and nothing has ever been resolved, and so it kept on going, until last week when I went to fetch my Venlor, and was told that I would not be supplied until I had paid the disputed amount (WHICH IS STILL UNDER QUERY)!!! So, the only way I could get my meds was to pay up. Kenny, the manager who said I would not get the meds until I paid was the one who suggested this. Now, I HAVE to take this med EVERY DAY, so I was forced to pay against my will for the disputed amount, as well as the current amount beofre I could leave the store with the med I HAVE to take each day. Kenny told me he would investigate, and would come back to me, on 26 Jan 202, (and that I would get a refund if Dischem was proved wrong!) Seriously? Is this ethical, is it customer care?
My reaction has been that I have cancelled my prescriptions with Dischem, and given them to Clicks, and I have vowed NEVER to enter that store again.
You have no idea how angry this has made me. Sincerely