just suggestion

I guess the reason why they asked you to quit is that they don't know what date is start date. I remember you have infopass appointment tomorrow. I encourage you to Infopass appointment. Maybe you could ask them to check for you about start date or they could give you a letter about start date. Anyway,no hurt to try!

Also, see this link for more information:
http://www.trackitt.com/usa-discussion-forums/i765/585543647/card-document-production-should-i-start-working