Jobseekers Benefit is a benefit paid based on your contributions into the social insurance fund (Pay Related Social Insurance) in the relevant year & is not means tested. This runs out after a given amount of time. If this happens then you would apply for Jobseekers Allowance, which is a means tested social assistance payment.
If you remain unemployed for the remainder of the year you may be entitled to a refund of some of your PRSI payments also if your earnings for the year are below a certain amount.
A tax refund from Revenue is a refund of tax paid during the year that you became unemployed. It is totally different to a Jobseekers Benefit payment from DSFA. It is refunded every four or six weeks. In your case you would get whatever is due all at once as we are now in a new tax year. If you do not return to work during that tax year you would more than likely be refunded most of the tax that you have paid that year. If you return to work during that year you would not get as big a refund.