Approximately 12 months ago myself and a co-worker were offered the position of joint GM within our business. This was a promotion from the jobs that we were doing. Along with the promotion came an increased salary. At the time our bosses said that they would trial this for 6 months to see if having 2 General Manager's worked. At the end of the six months they decided they wanted to see it over the next six months as they weren't sure. They've now come back saying that they want us to go back to our old jobs with our old salaries. Nothing was ever put in writing to this effect nor signed by either of us agreeing to this.
Question is - can they do this or do we have a valid argument to say that we'll go back to our old jobs but on the same money that we're currently on?