Learn English – turn over rocks for something – what does that expression mean

A bit of "poetic license" is often necessary in order to make a poem have correct rhyme and meter. In this case, "in their turn" is simply a way of saying "when the right time comes"; as you say, that time may be immediate.

But there may also be delays; if you manage to avoid getting zapped by the vault door, you can take as long a break as you want while packing up the gold before you have to confront the dragons at the next security checkpoint. And if by some miracle you do escape from the vaults entirely, there's still likely to be a team of bank enforcers hunting you down eventually, so "your turn" (to be punished) will still come, and then you will "pay most dearly."

I think what you are hearing is the slightly longer phrase: "I feel for that NOUN", which is a variant of I feel for NP:

I feel for [him].
I feel for [John]. I feel for [the parents].
I feel for [anybody who has to eat her cooking].
I feel for [that guy who had his house swallowed by a sinkhole].
I feel for [that poor SOB in Minnesota].

Feel for expresses your sympathy for the object of for: you feel sympathy or grief or dismay for that person or those people.