Brother, I cannot say anything about this. But, if the advertisement reads that the said one year diploma is must to be eligible for the post,it goes without saying that without the diploma then one is not eligible. If they had asked you to send the diploma along with the other documents, you were supposed to send the required diploma annexed with the application form by due date. In this scenario chances are high that you will be disqualified. There is beacon of hope: If the copy of the diploma had not been asked to send along other documents,at the time of the submission of the application, you are on the safe side so far. But you will have to produce the diploma before the interview call. Do not be disheartened if you get disqualified. Allah (JSWT) has decided something best for you. Wait for your time.
But if you are asking that because you have done Bs computer science you will not be required to submit the additional diploma of IT, it seems to have weight. As i have not asked from the authority concerned about this, i cannot say anything. You should call the Kp Tevta office. The contact number is available on there website.

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SHAH