Handed over to debt collectors for Lancet's stuff up.

I had a covid test in December 2020 with Lancet. They double charged the medical aid. The medical aid reversed one payment and Lancet reversed the other leaving the test unpaid. I have spoke to Lancet 4 time over the past 6 months, getting absolutely nowhere. The medical aid has arranged for the account to be settled twice now and finally this past week I see the account has been settled. Now I get the call from debt collectors.....How can Lancet's account management be so poor? How do you guys stay in business? All this for a mistake made by LANCET, not me or the medical aid. The best is, I get an email response from *** to say this is my problem and I must sort it out with the medical aid. Just shocking.