telkom is robbing us do not support them

im paying for a 4mg line for 3 weeks i been have a problem with the line speed( very slow 0.9kb to 1.4mg . finally after 2 weeks a technician come trough an test my equipment and the line and says there defitnaly a problem on telkom side he gave me a number to his senior in lenasia branch he said that there will optimise the line speed .after 4 days i called the senior back to find out the progress the guy told me that he optimised the line to a 2 mg line Not so (1.4 mg ) i told him im paying for a 4mg line he said that what he can do . I do not know what to do so i called telkom back i tried maybe about 20 time to speak to a manager an the call center agent just keep putting me on hold or cutting the call or saying manager, team leader or supervisor not avail or in a meeting can some one please help