A Problem With My Acer Aspire 4830TG?

I just bought a laptop Acer Aspire 4830TG recently, but I feel cheated because of the brochure that I received before buying the laptop, the HDD total is stated in the brochure is 640GB, but the amount of HDD stated in the My Computer is 580GB. And another one, the graphics stated in the brochure that I got the Nvidia GeForce 540M GT Cuda different than in the laptop is the Intel (R) Family Graphics HD. There is a problem here?

Any help would be appreciated

ACER laptop

Acer Aspire AS5253-BZ602 Notebook 15.6" 2GB Memory 250GB HDD 5400rpm DVD Super Multi AMD Radeon HD 6310