Vox fiber with frogfoot - worse than telkom dial up.

I have fibre from VOX with the frogfoot backbone. As from 2020-08-09 I have reduced speeds on my fiber line. For tonight I got 1M down and 5M up for a 100M up and 100M down line. I log a call every night, I get feedback every night, but it seems that the technological knowledge to find and sort out the problem does not exists.