This is a lot different than a crafting mistakes. The GMs are not there to fix and resolve every single mistake or accident players may make, they are there to resolve the issues that players cannot resolve themselves.
That is not guaranteed. While Blizzard may grant one or two exceptions, if it becomes habitual, Blizzard is well within their rights to refuse to grant a refund. Again, that falls on the player/customer to ensure they are clicking and purchasing on the correct thing.
It is not bad service to be told “no”. The sparks can be earned again, even if it takes a while.