Well person does not have to be a human, (Christianity has God, angels and devils as "osoby," but not"ludzie", literature can have elves, aliens and so on)
In casual speaking there is no difference, other than grammatical gender.
Does one get used much more than the other? I would go so far to say that in English, you really only use "human" when contrasting with aliens, elves, etc, or for some emphasis. Based on the course so far though, it seems like chlowiek has a broader usage in Polish?
Both are used rather often in Polish.
The way I feel it: osoby is about specific people, and with specific numbers , like a party for 24 people, or 5 people died in accident Ludzie is for People in general, sometimes meaning mankind/humanity, also for not specific groups and vague quantifiers
Osoba is a specific person, who did something, or needs something etc. Człowiek is human when you need to say human, and man in the old fashioned way that had man =human, also when referring to oneself, and in "one" construction.
Also often when man is not really about a gender, we say things he is a good man - to dobry człowiek. It is theoretically gender inclusive, but in reality almost always about man.
I reckon they should pay either one of 'this' or 'that' in this sentence