Promised chronic medicine would be dispatched - only sent FOUR days later

My prescription of six months ran out in March and the last pack I received was 27 February. I received and sent my new prescription on Monday 8 April, giving 4 working days for my medicine to reach me (as I have not received anything in March and was on the last few days of my chronic medication). On Friday 12 April I called the call center just to be told that I dint let them know it was urgent, and thus my medicine was never dispatched. Irrelevant if I didn't receive medication in March, the call center guy let on it was my fault. I took the blame, in tears, begging for my medicine to be sent ASAP (I have high blood pressure). They PROMISED it was collected at 15:00 and will be delivered Monday. I thought I would go past my doctor to collect my medicine this afternoon, as I managed to get (out of my own pocket), medicine from a pharmacy until today (Tuesday 16 April). Lo and behold - I get a message from Medipost today, Tuesday 16 April that my medicine was just dispatched and will arrive in TWO business days!!!!???? After I was promised it would be sent on Friday and delivered on Monday! THIS IS PATHETIC. I WISH I COULD BUY ELSEWHERE BUT I'M FORCED BY MY MEDICAL AID PLAN.