so saying your transaction fees should be refunded means you are indirectly saying that every node should purge your transaction from the block chain. And that would have been possible if you had made use of a fee below 6sat/byte. Probably only the node network of the wallet you used would have broadcasted it while other node will simply just purge it because of the extremely low fees.
Let us say the purging is 2.91 sat/vbyte right now. If the server of the wallet that you used set the purging to be less than usual, and you used a fee of 2.5, the server that the wallet used may make the transaction to be broadcasted successfully. But if it is by default and it is 2.91 sat/vbyte as it is Right now, any transaction with the fee rate below that will not be broadcasted by the server of the wallet used.
Also know that if the server has already broadcasted the transaction and later the server dropped the transaction in a way that the sender can spend the coins again in another transaction, if the sender decided not to spend the coin again, the sender should not be surprised if the transaction he thought to have been dropped later got confirmed because the unconfirmed transaction has been sent to other nodes and some nodes have different settings.
So if you want a transaction to be sent back to you, it is better you use RBF to cancel the transaction to send the coin to the address that you own.
transaction with a very low fee, that it is purged, what then happens to the fees since no miner included it in a block?
If a transaction is dropped from mempool, the fee will also be dropped because there is no transaction at all as the transaction dropped from mempool.
Just regard node and server as the same in my reply.
