No delivery

Hi my name is Charlotte, and i am an agent for Niche Hair Care, selling T444Z hairfood. On the 5th of March i deposited R3970 to order hairfood, money included R70 for delivery. I called them on Monday last week to ask about my order, i was told that it was with a corrier, not its almost 2 weeks and i have not received my merchandise. I called Niche hair Care almost everyday last week and everytime they picked up a call, it seemed to be new person answering the call on the other end, and i had to explain why i called, they would promise to get back to me, of which they never did, only one time did i miss their call, and they did not have information, i was told that it is being investigated. i cannot afford to lose my clients, i asked that they send my another order and they should sort out the lost merchandise with the courrier because it does not concern me. This thing is draining me, i do not know how much more of it i can take, and how long should i wait for my stock?