What to do?

[XennoX]

So I've been having insane problems with my ADSL line. The line will sync properly, but the SNR dropped from 33dB to 15dB in December. I've been running at 4Mbps for over a year, all of a sudden I find myself dropped to 1Mbps without them asking my permission to do so. So right now I'm going 'Wtf!?'

What course of action can I take to fix this problem?

 

[Shake&Bake]

None with Telkom really.
They guarantee the speed up to 4Mbps so they are technically ok.
Log a fault and see if they'll sort you out.