This is super annoying. It must be a Telkom fault. I am a WebAfrica subscriber and have been experiencing the same problem.
Traceroute through webafrica account:
1 <1 ms <1 ms <1 ms 192.168.66.1
2 6 ms 6 ms 6 ms dsl-185-88-1.dynamic.wa.co.za [41.185.88.1]
3 8 ms 7 ms 8 ms vl108.cr.gw.cpt.za.wa.co.za [196.220.59.238]
4 8 ms 8 ms 8 ms vl34.er.gw.cpt.za.wa.co.za [41.185.0.34]
5 154 ms 150 ms 148 ms upstream.vl101.gw.cpt.za.wa.co.za [196.220.59.226]
6 168 ms 161 ms 164 ms rrba-ip-esr-1-pos-8-0-0.telkom-ipnet.co.za [196.43.8.146]
7 177 ms 171 ms 165 ms rrba-ip-bssr-1-ge-2-48.telkom-ipnet.co.za [196.43.23.6]
8 179 ms 178 ms 174 ms nbsc-ip-bssr-1-atm-5-0-0-1.telkom-ipnet.co.za [196.43.23.30]
9 157 ms 153 ms 154 ms nbsc-ip-rcache-1-vif2.telkom-ipnet.co.za [196.43.22.222]
And then a traceroute through an Axxess prepaid account:
Tracing route to
www.telkom.co.za [196.43.22.222]
over a maximum of 30 hops:
1 1 ms <1 ms <1 ms 192.168.66.1
2 6 ms 6 ms 6 ms 196-210-152-1.dynamic.isadsl.co.za [196.210.152.1]
3 143 ms 141 ms 136 ms cdsl2-rba-vl2663.ip.isnet.net [196.38.73.25]
4 158 ms 161 ms 164 ms cdsl2-rba-vl150.ip.isnet.net [196.38.73.9]
5 176 ms 162 ms 155 ms 168.209.1.140
6 125 ms 128 ms 128 ms 168.209.1.170
7 178 ms 181 ms 177 ms rrba-ip-spe-2-wan.telkom-ipnet.co.za [196.25.127.181]
8 156 ms 156 ms 156 ms 196.43.25.137
9 171 ms 163 ms 158 ms rrba-ip-esr-1-ge-6-0-0.telkom-ipnet.co.za [196.43.11.166]
10 155 ms 161 ms 167 ms rrba-ip-bssr-1-ge-2-48.telkom-ipnet.co.za [196.43.23.6]
11 176 ms 165 ms 158 ms nbsc-ip-bssr-2-atm-5-0-0-1.telkom-ipnet.co.za [196.43.23.34]
12 165 ms 164 ms 172 ms nbsc-ip-rcache-1-vif2.telkom-ipnet.co.za [196.43.22.222]
It is also very time-dependent. Late at night it is fine - have not been able to test it throughout the day.