POOR LINE QUALITY

My line has been dropping everyday at 6 PM for the last month now, I was on a 10Mbps line (syncing at 6 Mbps). It was working fine for just over a month. Until it starting to drop to 2Mbps everyday at 6pm. I fought with Telkom, after two weeks of complaining and long calls to my ISP, telkom send out a tech to my house. But as usual these guys don't care about quality as long as the little DSL sync light is green and flashing they think the line is working fine. I continued to explain to him that my line dropped everyday at 6pm, and he then told me that hazyview local exchange cant handle 10Mbps, after i confirmed it with telkom wholesale in PTA, they tested my line before upgrading and that synced fine on 6.5 Mbps. the tech told me to downgrade back to 4 mbps, and that it would fix the issue cause i'm am to far from the exchange. very well i did so, and guess what ?,that same day my line was downgraded it dropped at 6 PM to 2 Mbps with SNR level as low as 6.2 and 5.9. that was the last straw, so I send telkom back another message on twitter. Saying the same thing happened and that they should fix it, I received an answer saying that they'll expedite my line, that was 2 weeks ago.