Tax refund question

My husband is PAYE and I am self employed but took no income from business in 2013.
Revenue did not allocate the Home Carers Tax credit to my husband in 2013 so I claimed it through my returns - he is the assessable spouse.
He paid 5300 in tax and 2800 in USC for 2013.
Got a cheque from Revenue this morning for 230. I assumed we would get the full 800 back.
Can anyone explain why we didn't?
Thanks
S

Just a thought!Whenever I have got a tax refund,it has been 2 cheques,one to each spouse.Maybe another cheque will be in Wednesday's post?