Attrocious administrative service and really rude call centre agents

Attrocious administrative service and really rude call centre agents. A year ago, I went to for a POLYCYTHAEMIA ATTENDANCE but before you have the venosection done, they have to check your Haemoglobin first to see if your HB is high enough. The results take a little while so because I was seeing my specialist, I put the paperwork in and had the HB test. My specialist told me that the venosection was not necessary so I went back to Lancet and asked them to cancel it. I got billed for it and I have been trying to get Lancet to credit me for a year. I paid for the HB test because I did have the HB test. Now they are handing me over for the venosection cost because it was obviously not cancelled and I was told by the call centre that I need to prove that I did not have the test ecause they cant go on my word alone!!! I need to get a letter from the specialist to prove that I didnt need it. It is absolutely ridiculous that a specialist who costs thousands of rands an hour now needs to give me a letter to say that I didnt need a test that didnt happen a year ago.