Fee Charged and short visa

long story short
I was student, married to irish national, have stamp-4 for the last 5 years, seprated nearly 4 years now, told DOJ everything, Have custody of the child, One boy, Got latter for renewal last week on the basis of custody of child.
Question Today went to renew my visa, I got charged 150 Euro and got ten days short in my yearly visa. My visa was up for renew next week on 4th April, Visa I got is only till 25th March.
Letter I received from DOJ didn't mention length of visa to be issued.
Thinking of writing to DOJ and visiting GNIB on tues to get 10 Days extra atleast
Any experience...

They make it up as they go along. Never expect anything to be right first time.
We got 4 year Stamp-4, I think yer man couldn't add

But as spouse of Irish, the permit should be free. There is no unique fee for "spouse of Irish, but separated", Until your divorced, your still married.
But everything is at discretion of Gardai,

Personally, I'd expect your visit to GNIB to go nowhere.
They will fob you off with something like " we cannot do anything once
permit is issued".
Some excuse, so they do nothing.

All you can do is be nice, and beg. Never know, might work if your lucky. But don't expect anything.