Downgrade but no downgrade.

I phoned Neotel end of January to downgrade my line from 8mbps to 4mbps and the person i spoke to said it will be done. I was assured it would be in effect from February and i can pay the new amount of R999. My line has not been downgraded and i am still getting accounts of R1500. I have contacted them again and sent a reply to their Billing/Accounts department that its incorrect, give them my account details but nothing. Their service and support is pathetic to say the least. I was really hoping i would be escaping Telkom to a more Competent Service Provider but no luck there. Now if they continue to ignore me i will just have to cancel my internet altogether.