90 days will be over soon - what now ? (Singapore)

Hi, is there anybody out there who knows (not only assumes) what I have to do, in case my EP application will not be granted in time ?
Due to some stupid mistake my EP application was only filed rather late. Now I am wondering whether I am eligible to apply for an Extension of 30 days (there is an online application for it, called eXTEND). On the webpage which is explaining how to apply it says somewhere that a requirement would be that you are not staying longer than 90 days... I am from Germany, therefore I was allowed to stay for 90 days in thef irst place. And these will be over soon. I called the ICA, but could not get more advice than this: Call the MOM to enquire about status of application. If not in time apply online for extension. My questions relating to the consequences of a situation wherein they say "in your case no extension is possible" were ignored. Would I have to leave for a couple of hours ? one day ? Or would I have to leave for 5 days? Or even more than 5 days?
Thankyou for your answers in advance. Best, Ulrike