@partnership, I retired in 2020, from Department of Education, and like you, Spouse and Children pension was deducted from my lump sum.
DOE provided me with an ITR2 form, which is revenue approved, listing the value of such deduction.
I did not contact revenue, until the start of the new tax year in 2021, at which point I was due to receive my PAYE/USC 2020 Statement of Liability from them.
I submitted the form ITR2 to them via my enquires, and they duly re-issued a second statement of liability, reducing my income, and refund of tax was given.
As you have retired this year, mid-year, it is also important to request from your payroll provider Form ASC12, as you may be entitled to all or partial refund of your ASC contributions only in the year of retirement, as these are calculated pro-rata. I never knew about this, until further examination of anomalies with my pension after receipt of the SCOAP in 2023 and pleased to advise, I got my full refund due from them.
Happy Retirement