This a profile of what you should be paying, if your tax credits are correct, taken from hookhead.com tax calc. :
Pay 3333,
tax 478
PRSI 111
Health Levy 67
For the year you would have credits of 3520, 9260 tax ( 5740 net tax) ,and the PRSI and Health Levy should bring it to a net pay after tax and PRSI and levy of 32124.