My complain isn't with ChatGPT, but with natural language. Even if GPT understands what you want, this interpretation needs to be stable over time and there's just no guarantee of that, and further, if you're actually programming in natural language as the original post suggested, it's not immediately possible to inspect how the language is interpreted.
This is a problem that humans struggle with too.
The two ways you typically end up getting around this problem with a programming language; a subset of natural language that uses very short and terse sentences with a simple and limited grammar;
BUY MILK(1).
IF EGGS EXIST THEN
BUY EGGS(12)
END IF
... or extremely laborious clarifications on the exact sense in which everything is meant, as seen in legal text which needs to be immune sophistry and various adversarial (mis)interpretations. e.g.
Locate, select, and acquire, through lawful means, one (1) carton of milk, being of a commercially reasonable grade, suitable for human consumption, and free from any defects that would render it unsuitable for its intended purpose; and
In the event the designated commercial establishment has available for sale, (12) one dozen eggs, the Designated Acquirer is hereby further empowered to purchase the aforementioned eggs, subject to them being in compliance with the prevailing quality standards for eggs.