What is the distinction between these two terms?

If Wells Fargo refuses to let me deposit checks because of something I said, are they preventing a transaction or merely choosing not to facilitate it? After all, I could open an account at another bank.

If FedEx returns packages addressed to me because of something I said, are they preventing a transaction or choosing not to facilitate it? After all, other shipping companies exist.

I can't find a bright distinction between the two terms, but there is a distinction between behavior directly related to business (such as where the money came from or what's being shipped) and unrelated things (such as what someone said in a livestream months ago).