There's only 3 unbanners here:
1.) Universal Unbanner (If this doesn't work, you're either using IW5M or got IP-Banned)
2.) Barata's Multihack (Which has an unbanner like the above)
3.) Tekno 188.8.131.52 Unbanner (Old one.)
If you're using IW5M, there's no available unbanner. If you're using Tekno and the above doesn't work it's because you got IP banned in which case you'll just need to change your IP Address.