There is nothing much you could do. Moving to maxis or Celcom means you'll be increasing the latency. I mean its wireless. So forget it. If you are a healer , and you are a lagger , you'll get your @$$ whipped (I mean you'll be kicked out of the guild , etc..Trust me). My advice is to call TM and complain. Just pray that they will resolve the issue ASAP. The other option is to use a lease line or 'SDSL' But then its usually overpriced.

Just to add this

218.111 IP is now solely for 4Mbps user and it offers the best latency to WoW servers (around 450-500ms - without any funny VPN services). Of course I've just tested in Stormwind on my friends laptop

So those of you who are thinking of getting good latency , upgrading to 4Mbps might fix it up

As for 4mbps , you can only get 218.111.x.y (whereby x is a fixed octet and y varies). In other words you can get ip ranges from 218.111.4.44 - 218.111.4.95 - thats about it , not more and not less