That's weird. speedtest.lon.websquad.co.za is hosted by Digital Ocean in their London DC - we monitoring this IP constantly and not seeing those levels. Give me a few mins to investigate.
On a side note, as-vuma.jb-is-pld-01.za.ws.net.za is an IP on the Vumatel network before handover (It's s routing IP on the Vumatel Core Network - in this case, an IP at parklands). It's not configured to respond to every ICMP request (so will often show loss or higher latency). As long as the spike there doesn't reflect on the next hop, it's merely that the direct ping between your PC and that device is not the greatest.