I am the only single like the OP has, lol!
I like that you raise the issue based.
I do not agree Cardano needs to create a pathway for such a stop-payment tx, I do however look at adoption and believe that such option would hold a high value in our space, not through the protocol, yet through a third party just as you were able to utilize the option through your bank.
I am a hardcore decentralization supporter and a realist, when I look at adoption I think of all the people like yourself that would love to be in control of your funds yet have some type of protection that we can utilize just like we do through centralized banking, options are good, there is no one way fits all, in this time and age we have many payment gateways we can utilize that have the stop payment option and with more and more people beginning to use crypto as a payment I do think that integration of insurance to protect people from scammers would be a good thing, however I see it as a 3rd party that operates with some style of central control as your bank does, and both parties to a transaction would be in agreement that by using the 3rd party they agree to the fine print that gaurantees insurances.
I say this knowing many people will not utilize smart contracts, most of us want an easy button, and most of us want financial security and insurances - there is no good reason for us to throw out the baby with the wash water, society has developed insurances for a reason and why would we throw all of that away? It should be optional and I believe slowly but surely it will be, I rank it in the same category as privacy and identity, and its multi faceted problems will at some point inspire someone to take up the task of building a 3rd party service that provides people with the flavor of crypto banking they would like to participate in.
All the responses tl;dr and maybe some a bit toxic to reply to, in the march toward decentralization integration utilizing the tools of the opposition will improve the path forward in this space.