H1 B Visa stamping rejected - Can I file H1 Amendment?

Hi,

I applied for H1 B in 2013 and after an RFE my visa got approved in Jan 2014. I appeared for interview in chennai consulate on 7th aug 2014 and was give 221 g white slip asking to re appear for the interview with the following documentation.

  1. entire package of H1 B petition submitted to USCIS
  2. Contract letter between Employer and Client
  3. Letter form client stating that I have a vacancy at the job location.

My attorney provided me with all these documents and I re appeared for interview today i.e 28th Aug 2014 and my visa got rejected.
VO told that the position was vacant for 7 months after I have applied but got filed later and I will be replacing someone who has been working in the position and hence my visa is rejected. But the client letter provided by my attorney says that I have a vacancy at the client location and it did not say what the VO has mentioned. Wondering where the VO has got the information from. how can I get it clarified?
When the VO says that I will be replacing someone - it means that I have a position available. Do not why my visa was rejected based on that reason.

Can anyone suggest me on my further steps. Is my H1 B petition still valid?
Can I file an amendment with USCIS for a different position at the same client or for a position with different client?
Any inputs are much appreciated.