Hi shels-07,
You are in a slightly different situation as you are being made redundant within 4 weeks of the end of the year.
You will not be making a refund claim on being made redundant, but will be making a normal end of year assessment of your taxes.
This is different. normally, if you are made redundant before the end of year, you wait 4 weeks and can then start claiming unused tax credits (for those 4 weeks and any more for how long they took to process the claim).
That close to the end of the year, you may not have unused tax credits (you may have received all your december tax credits) but you can claim for your medical expenses and any other income deductions and missing tax credits.