Refund and replacement are different promises

A refund returns money and ends the service for that period. A replacement keeps the service running at no additional cost until the promised outcome is delivered.

They look similar and produce opposite results for the buyer. A refund leaves you with your money and without the thing you wanted; a replacement leaves you with the thing you wanted and no extra charge.

Which one is better depends on what you were buying. For a product where the value is the selections themselves, replacement is straightforwardly more valuable.

What follows from that is less comfortable. Buyers frequently ask for the refund because it is the familiar remedy, and it is the worse of the two in exactly the situation where it is most often requested.

What to do with it. Read which mechanism a seller offers, and notice that the more generous one is also the one that costs the seller more to honour.