Can you refuse to do a job that is not the job you were hired for?

Yes, but at the risk of termination. Not all job duties need to be specifically stated at such a granular level - a job application form, contract, or performance appraisal process may include language requiring applicants to "perform other duties as assigned". Retail employee application forms do not specifically state employees are required to clean the sales area, stock inventory, process transactions, or dress in a certain manner, but those are understood/implied by accepting the job.

The same holds true for a higher position - a CEO may not be hired with specific duties detailed, but failure to perform to the stockholders demands may result in calls for termination.