Letter to Doctor- NO SERVICE TO STANDARD OPTION

My pediatrician informed me that they received a letter from Bonitas instructing them for us to pay cash until further notice.I called bonitas & spoke to Bervely who explained to me that bonitas never sends letters to service providers, rather they send to their clients directly.If doctor received a letter then it must be invalid.I called the practice and got the copy of the letter & send to Bonitas.Thandi Motha called me instead and explained same thing Bervely did,then I asked her to send me a letter in their letterhead indicating that they never sent any letter to service provider.she asked for doctor practice no. to check if doctor is within bonitas network & I gave her doctors initials & surname which she indicated they wont help her.then she sent list of the doctors in my region.the very 1st name on the list is the doctor in question.I alerted her responding to her email,next thing Nthabiseng responds to that email taking me back.I alerted her matter is being held by Thandi.I made a follow up today,now Fikile Matlasela responds with a closure of query.BONITAS SHOULD SEND LETTER TO ME FOR ME TO SEND TO SERVICE PROVIDER,INDICATING THEY NEVER SENT ANY LETTER TO THEM AT 1ST.