Attorneys using me

Hi, I need your help. I was admitted at Medi clinic hospital and was seen by a physiothe******. My medical aid did not pay them and they told me they will resubmit the claim. They never returned to me after and I assumed it went through. Then after I received a call from collection people, saying my account was handed over. I spoke to the guy and we settled in me paying R300 a month until the dept was finalised. He also told me that I had to ensure that payment must be done before the 7th of every month. Then I made the first payment on the 4th of the next month. Few days after I received summons saying I did not honour the agreement, I went to the Attorneys offices as I wanted to get clarity of what happened but he was not there. I decided to just settle the whole amount on that day and I wrote an email to him and I attached the proof of the final payment. I have copy of those emails. For this month I see they taken R400 from my salary of which now I dont understand it for what. Please help me