What they mean is they know what you were on already and decided they wouldn't give you any more. They probably gave the less experienced person that they appointed the 70% - maybe less, if they buttered them up with a load of horseshit about "great experience" and "opportunity to review in due course".
I hate this kind of thing. I went to a third job interview where I was asked by the HR director what money I was on in my current job (underpaid, part of why I was looking around). Of course I told the truth - what idiot would lie in a job interview? In my mind this was a completely separate point - a matter of fact - from a question that would open up a salary negotiation, and I was too inexperienced, and hustled on too quickly, for me to open up that negotiation myself.
I was soon offered the job on the exact - low - salary I was already on. I did open up a negotiation and I did get closer to what I wanted, but it wasted time because they should have been prepared to talk turkey in that third interview and it made them look a bit like dicks to me. I took the job anyway, and after a little while I was interviewing for a junior to me. the same HR director came into the second interview with me and pulled the same dick move on the guy I wanted to offer the job to - she asked his current salary and then afterwards told me that he could be offered that, and no more.
Of course to his credit he explained that he was looking for a pay rise as part of his reasons to move, and that offer wouldn't do. I took it to my boss, didn't even attempt to argue the HR position and just presented it as "we're being twats if we don't give this candidate the reasonable salary he is looking for, and we shouldn't lose him". It worked.
anyway to cut a long story short, what that HR person was effectively trying to do was to cut through the advantage of negotiation that people changing jobs temporarily have. Once you are in a job / company it is really easy for them to put pressure on you to accept the status quo, which amounts over time to a real terms gradual pay cut - your experience and value to the company increases, inflation takes effect, and you are getting a worse and worse deal year on year. for some stupid reason - I have no evidence that it ever worked - she believed that she could apply this same pressure to people looking for new jobs. (Is this standard practice? Does it ever work?)
In your case I think if you want a pay rise you will have to look externally. They have decided they've "got" you and you will have to sell yourself externally for a better deal. The irony is that your experience actually makes you of higher value to the place you're at. They just don't want to reward it. So they'll end up with someone cheaper and less valuable.