Unpaid bill since 2015!!!!?

So firstly I wish to state that the service I have been receiving is really pathetic as if I'm not paying for medical aid!!! On 1 July 2015 I joined the hiv programmes, in August 2015 I went for the scheduled blood tests, after that I've been getting calls from Lancet Lab stating that I'm owing for the blood tests. Question is, why was this not charged to the B24 code and is it not part of the programme??? Very appalling!!! Secondly, 16 January 2016 yet again the Lancet Lab is harassing me and have threatened lawyers on me for none payment, why was this not paid because the Dr charged to B24 code and there is funds in the medical aid!!! Funny enough, you people are quick to pay the Dr's for consultation but not for my blood tests!!! I need this sorted asap as I'm tired of being harassed daily and being stressed in the condition I'm in, no one seems to care but just to keep putting under stress for things that are not my fault... You people will liaise with the Lab and sort this out with your own solution, I am not paying because I'm on the programme... I want this sorted by close of business tomorrow!!!