taxed on my tesco turnaround shares

lotsontop

I was awarded 219 Tesco turnaround bonus shares worth £350 on 23 may 2016. I decided to hold them hoping that they would go up in value, rather than take the money straight away.
I was then sent a letter confirming all the details only to find they have deducted 71 shares totaling £113. This deduction is apparently for tax and NIC which is estimated on my taxable income for year 2015/2016.
My tax allowance is £11,000 I don't earn anywhere near that. So my question is why have I had this £113 deducted??
Can I claim it back??
It seems that if I had taken the bonus immediately I would of received all the £350. I cannot understand how I have lost this £113.
I would be very very grateful if someone could shed any light on this problem as it is really troubling me.

xylophone

http://www.verylittlehelps.com/dloads/UK%20Turnaround%20Bonus%20booklet.pdf

Go to ourtesco.com? (Employee site?)