AGS COLLECTION WANTING MORE MONEY THAN I OWE

I got a call from AGS collection saying that they represent a doctor that I once to concerning a medical bill that my medical aid did not pay. I spoke to a lady called Palesa and I asked her to send an sms with the banking details where I should pay. I also asked her to give sms the balance as well. On the 26 of May 2015 at around 15