incorrect Billing

I took a legal aid cover with Clientele legal assuming they would be better than their competitiors. Boy was i wrong. Firstly they decided to debit their premium on the 21st not the 25th like we had agreed. Then they send me another sms that says they will debit me again 14 days from the 20th of the month. Trying to call them has proved fruitless. Im always caller number 20 and i never get through. I have been trying for a whole week.