a credit card company put a garnishment on my bank and took my savings and will take every penny of any child support checkes i deposit. can they do that considering its child support.

They can't take child support, disability, or social security. Only a % of your paycheck based on your state laws.

If I were you, I wouldn't be putting that money in the bank if I needed it to feed my child.

If you deposit the checks into the account, no one can sort through and tell you which funds are coming from where. I'm surprised to here that they have garnished your account. Did you apply for a card through your bank?
Most times, the credit card company will just let you keep racking up your bill. They make their money on the interest it occurs. I would talk to a legal professional, and talk to the bank, and inform them of what's going on. That their are transactions on your account that you haven't authorized. They may be able to help you and stop payment on such garnishments. Next is to contact the credit company and either cancel the card and arrange a payment plan, or freeze it until you pull out of debt. Good luck to you