Career Advice Bait and Switch

I was recently hired as an ED at BB on the strategy team. I spent 10 years combined at an IB and then a very large Asset Manager. The strategy team is working on some great initiatives. Since being hired I have been asked to focus more on operations / transaction management rather than strategy. Operations is not something that I am interested in and I am seriously confused about what is happening. Luckily, I saved down the job specs when I received the offer so I know that I am not crazy, as operations is never mentioned in the description.

Does anyone know what I can do here? I have other options, I can easily leave and go back to fintech, but I really am interested in the original position I applied for and was hired for. Should I go to HR and make a complaint, or should I reach out to MDs that I know are working in the area I applied for?

Any suggestions are appreciated.