VDSL speed misleading

<p>I have had a business ADSL line since 2013. The speed is horific so I looked into various faster connections. I contacted Telkom and they told me that I could get a VDSL line with a speed of 40. I app**** and last week I had it all setup. My speed test only shows a speed of 15. I queried this and was snet from one department to the other and told to log a query. This I did. Someone said the speed all depends on distance from exchange as well as the quality of the line but that I should get at least a speed of 30. I told them that I am only getting 15 and they said they would send out a technician. I have received a message saying that my fault is resolved and yet I still get the low speeds. I have now wasted money (IT costs, new router etc) and time and have got no-where. Surely the sales department should not be selling this product if is a luck of the draw scenario? I would have appreciated correct info to enabl me to have made an infor,med decision as to which supplier to have gone with. What must I do now? There is a huge difference between 15 and 40 when it comes to speed.</p>