You may not get it all back immediately and it may take a several incremental P50 claims to get it back. That's how it worked for me when I was unemployed. Basically I think they refund an initial amount and then tell you to contact them again on a certain date if you are still not working at which point the refund another chunk and so on. I presume that if you have paid €3,245 in tax and your credits are €3,120 then you will indeed get back €3,120 eventually. PRSI is not refunable unfortunately.