No response on email sent a while ago

I am beyond disatisfied with the treatment I recieved from the medical aid.

I sent them an email last week Friday and recieved absolutely no feedback until I had to again call yesterday only to be disappointed by the response I was told.

Why does no one take just five minutes to respond to an email and us as the customers have to take the initiative to call again in order for us to recieve a reponse.

I will be offcourse leaving this medical aid and joining something else.