I don't know how they (SE) could be any clearer, really.

Not only does it warn you first on the Transfer page about why you can't Transfer, but it then warns you in the game that Relinquishing a Plot of land means you "give it up", as in, no refund at all, you give it away.

It even asks you to confirm.

It clearly states the condition to receive a refund, you must be on a Congested World, and you must select a New or Preferred World, the give away is, its Free.
If it asks you to pay, you messed up reading.

They will not help you at all, as you failed to heed the warnings and safety measures.