401k? I have a plan with Merrill Lynch through Walmart and have about $4,400 invested, but I can't pull it out?

When I called they said that for me to pull any money out I had to be either 59 or no longer with Walmart, the other option for me was to file a hardship if I was having problems with something like medical bills or am being evicted and only then I would be allowed to pull out around $1,000. I was told by a relative that I could pull this money out at anytime even if I am under 59 and I would only have to pay a penalty and then taxes at the end of the year. Is there a reason why I'm not allowed to pull this money out?