Harassment by staff

I went for blood tests last month and the medical aid paid a portion and I was informed that I need to make co payments. Which I agree on. However I am being harassed and indated with phone calls and sms’s!!! The account is not even 30 days overdue and Lancet is carrying on as if I’m about to make them close their doors or planning to flee the country !! Hence my refusal to make use of them in the past. It is ok for them to make you as a patient wait because they are on smoke break or on personal phone calls but your blood is still underway to the lab and they start harassing you.