Poor administration and payment reconciliation

I have experienced great difficulty with getting Lancet to reconcile my account statement over the past 5 months. I am called by a different consultant each time without knowledge of the various proofs of payment I had shared at least 3 times already. The matter has been escalated twice internally with no feedback on my submissions, only to now be called by a collector assigned by Lancet. This is incredibly poor administration which is a real shame considering that their actual lab services are quite good.