Lancet proof of claim

I was admitted in hospital last year december, now i owe Lancet over R7000 because the medical aid did not pay for blood test, Bonitus sent me an email saying Lancet never sent a claim. Lancet says they sent a claim it been almost 4 weeks waiting for Lancet to provide proof of claim.and i keep on getting calls from their collection agents.can you ask Lancet to gove me that proof that they claim from Bonitus , so Bonitus can tell me why they did not pay