When you ask a merchant to reverse a charge so you can use another card how are

If the merchant is batching their charges at the end of day, like in a retail store, you will only see the final charge on your chosen card. The charge that was reversed shouldn’t show as a charge/credit since it all happened within the same day’s batch. Basically, the initial charge/credit cancels itself out in the batch.

I hope this answers your question.
Cheers!
Krista