Hi, Veera:
Generally, Customs & Border Patrol ("CBP") issues B-1 or B-2 visas somewhat interchangeably. Two issues here:
1) What did you tell the officer when you entered? If you told them what you were planning to do, then they probably issued the B-2 in accordance with that. If you're convinced they made a mistake, you could go back to the CBP office and ask them to re-issue a new I-94. Before you do, however, you should certainly consult with a qualified, experienced immigration attorney. You could inadvertently say something that would make CBP reconsider their decision to admit you. Which leads to my second point...
2) If you entered for business, be careful. Even if you get a B-1, you are only allowed to engage in commercial transactions not involbed in gainful employment -- for example negotiating contracts or consulting with clients or business associates. You could also attend a business convention in B-1 (or B-2 for that matter). If you're thinking of doing anythng in the USA where you'd be paid in the USA, you are entering a complex area that could jeopardize future immigration options.
Consult with a qualified, experienced immigration attorney to diiscuss your plans. An early visit can make sure that you have time to explore and exercise all your options.
If you're arround the Philadelphia area, call my office at 610 664-6271 and set up an in-person consultation; if you're farther away, we can set up a phone consult.
If you don't contact me, I urge you to consult with an experienced immigration attorney who focuses their practice on immigration law and is active in the local American Immigration Lawyers Association (AILA) chapter.
Good luck!
John
john@hvmmigrationlaw.com