Paying for a 6Mbps line but only have a 4Mbps line

During May 2015 I was contacted by a sales consultant at Mweb that asked us if we would like to upgrade to a faster line and I was able to afford the 6Mbps line, after this was apparently activated I did a line test which indicated that we are only receiving a 4Mbps line speed. I logged a complaint as the line was from Telkom but we are paying Mweb for the line as well. We were contacted after this complaint were logged from Telkom which told us that Mweb knew that we could not get a 6Mbps line for the area where we stay but only a 4Mbps line was possible. I then asked Mweb to put me back on the 4Mbps line as Telkom assured us that a 6Mbps line was not possible. For the second month I am paying for a 6Mbps line but I am only have a 4Mbps line, I would like to know how many other people pay for something they do not get and what are you planning to do about my account Mweb?