Game breaking lag during peak hours

ISP:
BT

Type of Internet Connection:
Fibre Optic

Internet Connection Speed:
30mbps

Modem:
BT Home Hub 3.0

Date & Time:
Between around 18:00-22:00 BST

Frequency:
Always around the above hours

Character Name:
Curjos Panthera

World:
Ragnarok

Area and Coordinates: Various - very few unpopulated areas are lag free, as are instanced areas.

Steps:
When in populated areas, I am getting delays between 10 seconds sometimes up to 60 seconds. This makes it impossible to play the game during peak hours outside of instances. Even though I am getting huge lag in game, outside of game (e.g. in browers, other games) the connection is as normal.