If you were paid on 5th March, then the end of that period of 28 days must have completed on 15th March - 10 days later. That was a Saturday. You left on 13th March, which was a Thursday. You therefore should have forfeited pay for one day on that period - Friday 14th March. This is one twentieth or 5% of your normal period's pay.
You didn't say how much you earn, but unless it is around �2000 per period, too much has been deducted.
That's the way to work it out, anyway.