Re: I don't think the problem is Excel
The fact that Excel is the wrong tool for the job is irrelevant here. Hasn't anyone heard of reconciliation totals. At its most primitive:
number of tests received at centre = number of tests sent = number of tests done
Either the person "designing" the system had no idea or, more likely, their manager thought it was a waste of time.
Punishment should be to be taken back to the 60s and made to feed several boxes of 2000 cards into a card reader which rejects 1 in 100 while the PFY drops several handfuls onto the floor. Reliability breeds laziness.
Excel does have a purpose here - it's presenting the reconciliation totals for all files received.