ADSL line speed dropping. 3 calls logged

I have now logged 3 calls with telkom as my 4MB adsl line keeps dropping its speed. Today I am at 2.8MB. Have logged 3 calls over the last 2 months and still nothing seems to have been fixed. The last call was escalated 2 times but no responses from Telkom. Think it maybe time to find alternative supplier for my Internet access as Telkom does not seem to be able to provide a decent service anymore. Try logging a fault and you have to wait for 30 minutes before somebody answers and then just drops your call.