I have a a money issue with TMNet too.Off course I have make complaint and whatever black and white to support.
Along the way they sent some not nice e-mail and I answer back.
I refuse to pay them the disputed amount for more than 2 years.
I just pay the rm66 every months but not the disputed amount.
I hold the money (about rm280 ). Eventually after 2 years , they agree and I pay about rm260.
So for rm20 dispute , I hold the total amount for 2 years.

You should do the same.Just don't care, pay rm66 and let the diffeent accumulate and when its 1Mb line then pay rm77 (but before paying that , plse minus whatever you had overpay them)

The money is in your hand.They had better come out a better way to take your money.

I had the 512 Kb for more than 2 years. My average dl is 430 Kb on good seeds.
Then I have the 1 Mb line.My average dl is only 470 Kb eventhough I can hit 820 Kb at TMNET speedometer.
The speedometer test is quite useless cause it only measure a SINGLE transaction to TMNET FTP for 10 SECONDs only.

So unless you are lucky , there is only a very slight improvement in dl speed.

If I have known , I will definitely NOT choose the 1 Mb line.
So if you are doing fine ,DON'T go for 1 Mb