What is TXN decline charges?

Could you please clarify what you mean by "TXN decline charges"? Are you referring to transaction fees associated with a specific cryptocurrency or payment network that increase when a transaction is declined or fails? Or are you asking about charges imposed by a financial institution or service provider when a customer's transaction is declined due to insufficient funds or other reasons? Without more context, it's difficult to provide a precise definition, but I can offer a general explanation of how transaction fees and decline charges can work in the cryptocurrency and finance industries.