Having been a part of their Customer service I know your frustration, The 'system' is not very good. Very stressful place to work as we do the best we can then other depts/people let us down and we take the flak from the customers who then think we did nothing even though we tried our best. sigh
Anyway I have the 6mb package too and my DL has ever dropped under 5m or my UL under 500kp except once or twice in the last 2 years due to an area problem or whatever. Not everyone is as lucky though