Shambolic admin system at Lancet Laboratories

Lancet has a shambolic administrative system. It has been some 3 weeks now since I paid for a blood test in cash and I am still waiting for Lancet to provide me with a tax invoice which includes my medical aid membership number. Without the number included, the medical aid will not consider a refund of my expense. Lancet keeps "escalating" the matter (whatever that nonsensical corporate speak means) but there is still no invoice.