Salary (Software Industry) - why an experienced engineer is getting much less than a fresher?

I joined a company, and I got only a 30% hike—4.5pa. They told me that they can't give a hike more than 30%. But when I inquired from freshers, they told me that they were getting 8pa. Can anyone explain to me why an experienced engineer is getting much less than a fresher?

Are the freshers working in HR or other department?
I presume 4.5 and 8 refers to amount in lakhs???
Also they may be having some qualifications which the company urgetnly needs in core areas of business.

They all are software engg and I am also a Software engg and they are working together .

Why are you asking us now Rajeev ? You should have done enough enquiry about it before confirming the offer made to you during the interview. Without doing that after accepting the offer and joining now you feel disappointed (or cheated?). Having accepted the 4.5 pa package you now has no locus standi to raise a dispute with your HR quoting other freshers are fixed double of your package. It shows poorly on your bargaining power. Presumably they are not at fault either. They are not under any obligation to reveal what package was given to the freshers and other serving employees. It's a prerogative for every employer to fix packages to a prospective employee, may be, first on your quote and the counter offer by the employer then a package is settled in between. It's your failure to do due diligence before fixation round was on and accepting their offer. Now few options available to you are (1) Raise a demand or some sort of an anomaly for a higher package quoting the package other freshers drawing, giving an ultimatum that failing which you would prefer to quit and to await employer's response (2) Remain there itself and look out for other openings during the probation period itself (3) Go back to your erstwhile employer itself for the present requesting them to cancel your resignation and wait and watch for a better options having once bitten.

Hello Rajeev,
A few queries to get the factual picture right.
1] From which Institutions are these Freshers?
2] How are you sure that what the Freshers say--that they are getting 8 L p.a.--is absolutely right? Quite often, freshers jack-up their CTCs for 'effect' & 'bragging'.
3] What's YOUR exp level & Skillset?
However, in general, a Raise of 30% is normal in the IT industry--though this doesn't mean some don't get >30%, but that would involve an exceedingly good I/V performance OR the skillset being tough-to-get OR the requirement being very urgent.
Pl confirm the points stated above to enable the members to give better clarity to your situation and/or make suggestions.
Rgds,
TS