Okay. You've done a silly thing, but you're lucky you've figured it out this quickly. Things to do:
1. Probably goes without saying, but DO NOT send Ta Mart-Services, Inc. ANY money.
2. DO NOT spend ANY of the money you were sent. If the check was for $500, act like you have a $500 hold on your account. If you spend the money, you will be held liable by your bank!
3. Call or go to your bank first thing. It's very important that they know that you didn't intend to commit fraud. They won't close your account if they know it was an honest mistake, but they will if they believe you're trying to steal from them.
4. Be prepared to see all of the money you were given disappear from your account. The bank will take it back quickly, since you're telling them it's a fraudulent check.
5. Post your own review of the company that sent you the check so that others can learn what you did.
6. Consider filing a police report, just so they're aware that this scam is operating in your area. What these people are trying to do is illegal. Talk to your mom about that.
Rule of thumb: you will NEVER receive unsolicited checks in the mail. Ever. Period. If you get a check in the mail you weren't expecting, tear it up. It will always be a scam. Secret shopper scams in particular are very common--being a secret shopper is easy, fun, and lucrative! Don't fall for these scams.
Also, anything that requires you to "deposit the check then withdraw the balance minus [your] pay" will ALWAYS be a scam. Always, always, always. There will never be a legitimate reason you will be required to do this!
It's a scam. Contact your bank tomorrow and they MIGHT waive the bad check and other charges. Do not withdraw any more cash based on THIS check, and don't spend any of the hundred you already have, and don't do any Western Union Moneygrams or similar transfers.
Your mom is correct.
The check was fake.
Make sure that you have enough money in your account for when it bounces.
Your bank will hit you with a fee when the check bounces but, as long as there is enough money in the account when that happens, you should be OK.
You have been scammed. If something is too good to be true, is usually is. How much money did they take you for. You will be responsible for any bank overdrafts.
Take care