This happened to me along with every other nasty trick in the book at my last job. I was told I was being hired at the same pay as the last person and found out very quickly it was only 60% of what the last person had been paid. The pay was well below the industry norm so I after trying to work it out with them and getting the run around I quit. To retaliate they never paid me my last check and when I confronted them about it they came up with some nonsense about accidentally paying me for a vacation I took 2 months prior to my resignation. The reality is that the CEO is an egomaniac con man who took it as a personal offense that I rejected his lies by quiting.
I would say start looking for new work and then confront them about this discrepancy and ask to be raised up to the same pay rates.