Word for Negatively Surprising [duplicate]

I'm searching for a word representing "Negatively surprising", or "Negatively amused" in an appropriate form.
Example:
Someone who proclaims he aims to do things in the right way has done something in the completely opposite way.

How could you have done such a thing?
That action is very ___.

Said with the purpose of showing the contrast between the expected and the actual, and asking for change to adhere with his set goals, instead of just pointing out disappointment.

It is different from What's a word for being disappointed in a surprising manner? because it asks there about surprise of being affected by the disappointment. The meaning of surprise here is different.

shocking:

that offends or upsets people; that is morally wrong

Oxford Learner's Dictionaries

Oddly, this definition does not mention the "surprise" element. However, if you look up the verb "shock," you'll see it is defined as:

to surprise and upset somebody

So a "shocking" action is both surprising and morally wrong (or perhaps just offensive or upsetting).

By the way, this word expresses a rather strong feeling, but since you say you want a word that describes someone who has "done something in the completely opposite way" from the right way, I'd say it fits.

However, if you're actually talking to the person who has negatively surprised you, Josh61's suggestion of "disappointing" may be better. Compared to "shocking," I would say "disappointing" puts more emphasis on your feelings of being let down by this person, and less emphasis on the elements of surprise and wrongness.

Disappointing:

• that fails to to satisfy the hope, desire, or expectation.

also frustrating may fit:

• preventing realization or attainment of a desire.

The Free Dictionary

I believe sumelic's answer, shocked, is the best word for a strongly negative surprised reaction, but if you're looking for a milder alternative, you could consider taken aback.

"When Susan accused me of cheating I was completely taken aback."

It means to be both surprised and disturbed or unsettled at the same time.

I suspect it is a reference to the physical act of backing away or leaning back when startled.

It comes from a sailing term referring to the sails being pushed backward against the mast by the wind, but is more commonly used to indicate unpleasant surprise nowadays.