This can happen if there is traffic of orders in the specific organization that is to offer this service. It can also be as a result of giving a wrong address. Consult with the respective authorities to get more detailed information on this.
Did they send you any paperwork to update your case? You sometimes need to renew your information about income every 6-12 months. That would stop food stamps from coming if paperwork not returned. If that is the case you would need to start application process over again. It's rare food stamps would arrive late.