It's really tough to answer you question without a lot more information. The problem could be at any stage of your DSL connection route - your PC, local network, router, Telkom exchange or with the destination server that you are trying to access. If the problem was on our network, we would see several clients with similar experiences, which we are not at present.
The best would be to start by basic troubleshooting. Run our Network Test App and also a speedtest.
If your latency is high at the first hop (to your router) it is either a problem on your PC, local network or router. If the second hop is high (in the traditional setup) this usually points to a line fault or an exchange fault. If the latency is high only at the very last few steps of your trace, then the problem could be on the destination server or the hosting network.
The network test app will give you the option to send our suppor team they results so we can help you understand them.