if your role was no longer required then I think the legal stance is that the position cannot be filled for 6 months, without contacting you first. check acas for details.
either way, maybe give them a ring and say "i see you're advertising my job again. can i reapply?".
I'm not 100% sure it's my old role as the company and town weren't given, only the area. I rang the agency advertising it but they wouldn't tell me which town.
It depends how good the redundancy deal you got was. If its the same role advertised you could put up a case that redundancy did not apply and establish the case for unfair dismissal - with the redundancy money still in your pocket of course. I'm not suggesting that you would get the job back but you might extract more money.