Did this when I was 26 - found a new job with Company B, was offered more to stay by Company A, took it. Stayed 12 months, realised that the reason they were not not paying me it originally was because the role was not there. Left to join Company B.
Am now 36 - my advice 10 years on is leave. In truth, most people who are switched on don't leave for money. They leave for opportunities, location, control. If you are motivated to look for a new job, then you probably have better reasons than money.