Given the timeframe, odds are that your resignation was never processed or if it was ever put on the system it was reversed out again. Quick rule of thumb - if your employee number changed, you're probably a "rehire", if your employee number didn't change, you may never officially have left.I don't know what the legal technicalities are in your situation but a reasonable minority of people resign and change their mind shortly after (usually bribed back). Similarly, people can be fired then reinstated when they appeal. Either way, there is some leeway in the process to allow for reversing out termination of employment.