I excepted one type of job but once starting the employer was forcing me into a different job

I excepted a job for packing in a warehouse , there was nothing at any point that indicated it could change or that I would need to get on a forklift. I accepted my position based on knowing I could do it. Once starting I was told I was going to be forced to do a different role and also have to learn forklift to do it. My position was still available to work and had no forklift in it. Im fine with helping out other departments and learning new roles but I was not warned of the forklift position as mandatory or that I might not even get the job I excepted which was clearly defined and had nothing indicating any possible change could happen or indication I would have to do forklift as a possiblility. They told me they wanted me more for the other position but that was not something I was comfortable with. Is it legal to force this issue? There was no informed consent or anything prior, should there not be something to indicate this prior to exceptance of my job I knew I could do?