Me being from Mumbai, India, I have travelled to Belgium twice before once in September 2013 and June 2015.
For my most recently completed trip, my Business Visa validity was from 30th May to 16th July for a period of 48 days. However, there was another "Duration of stay" mentioned on my visa which was 30 days (which I did not observe)
While applying for the visa I also had produced my return flight tickets which was from 30th May to 6th July. I had applied for a business visa from a visa consultant (and not myself) and he applied for a short stay visa which is only valid for 30 days but my travel time was for 37 days so he should have applied for a long stay visa which he did not.
Now, while on my way back from Germany (entered Belgium and left from Germany in June, 2015), I was not caught at all at the immigration neither was I caught at Mumbai and only when I applied for another Business Visa on 4th July, 2016 (an year later) for Belgium again, I got a call from the embassy on 5th July, 2016 asking me the reason for overstay, while I truthfully did not know that I had overstayed because I somehow ignored the 30 days validity and only considered the 30th may to 16th July,2015 (48 days) as valid travel dates, I explained the person that this was a genuine mistake from my side and I didn't know the validity of 30 days. The person said, my application needs to be sent to Brussels for further approval and my client in Belgium spoke to the concerned department regarding my application and got an update that my visa has been rejected.
Moving ahead, my tickets are still booked for 4th August 2016 to 16th August, 2016. Would it be wise to reapply for a visa to Belgium itself or should I apply it for some other Schengen country ? Will it be rejected the next time as well or there is a 50% chance of getting approved ? This time application process should be any different or the same ? Should I attach an apology letter ? I would lose a big business opportunity if I am not able to make it to Belgium so any help here would be highly appreciated :)
P.S. Due to this rejection, will I also be rejected to all the other 1st world countries visa applications ? Can I do anything to undo this ?