Paying for 4MB Internet Line but only getting 1MB

I have recently installed a 4MB internet line from Telkom however my download / streaming speed never ever exceeds 1MB. After calling the 10210 contact centre number several times, I was informed that Telkom Cape Town will fix this on the exchange however nothing solved the problem. I have also walked into the Cresta branch twice with this problem upon which I was told \Telkom can offer me an alternative service"and they are not technical so they cannot help me. This is pathetic customer service from Telkom who is advertising 4MB internet speeds and ripping customers off by supplying 1MB true speed. Most of the time I get 54kb"