There is absolutely no chance there are no test cases and results.
I work for a large UK govt body and have done on and off for the last 16 years as a contractor and supplier.
There is zero chance that these test cases and their results do not exist. Zero. Zilch. Nil points.
We would not get paid if the systems was not tested and the results recorded. It didn't matter if it was as a large supplier or in house as a contractor.
I know where all the tests done are for all the systems going back 10 years as they are recorded. They have to be recorded as that was a condition of going live.
Somebody somewhere is lying through their teeth...