I got a paper to review from a journal that had rejected my earlier works, how to respond?
These two issues are separate: if they reject your paper without comments, that's where you have to complain. They did not do a good job, reputable or not, and you are entitled to an explanatory review, especially since they wasted your time.

But you should not link the issues. If you think the journal is not as good as it used to be, you can decide not to review. If you think it is good, then, depending on how much time you have, you can offer to do the review. And if you do, do it with as much goodwill as you would for a journal that gave your astounding reviews.

But you should not link your rejection and your review - it is tempting to do so, but it is not a professional attitude. And you want to be just that: a professional.