Access to Feeds.SubmitFeed is denied

I am trying to connect Seller Partner API from C# console , but it will gives error "Access to Feeds.SubmitFeed is denied" for SubmitFeedRequests . Passed all required parameters i.e Action MarketplaceIdList Merchant MWSAuthToken FeedType ContentMD5Value AWSAccessKeyId Timestamp Version SignatureVersion SignatureMethod Signature Please suggest .