HI
Same problem here
Mweb uncapped 4mb (not premium) the most i've ever dloaded is 112gb a month for the last year.
This month stands at
32gb. My torrents download at 1-2kb max 32 kb.
After 7 at night,
they do not move at all.
This morning I was trying to download gimp with utorrent.
Mweb was going at 18kb for over an hour. In desperation I switched to my 1gb free account
with afrihost and it immediately shot up to 412 kb and finished in a jiffy.

..
Note: Speedtest.net report normal pings/responses, ect, as does the mweb speed test itself.
Sometimes the net gets so slow that gmail does not open (on separate machines) although my ping in LOL/ DOTA 2 is mostly constant. Putty struggles to keep active telnet connections.
So, on to attempted cancelling.
----------------------------
At Mweb, I saw there is an option to cancel my adsl under the my products on account. Great!
I click it aaaand... Wait a minute ...
One Time PIN
We have just sent a unique One Time PIN to your cellphone number: *** *** 1394. (Not your number?)
This PIN helps to protect against fraudulent use of your account.
To continue with your transaction, please enter the PIN below.
One Time PIN:
Alright. A pin. To a weird suspiciously foreign looking cell phone number i've never seen before in my life.
Not your number shows The cellphone number you have registered is: 27843301394
------
Alrightly
Let me check my account details to see if somehow we registered a mysterious number which our OTP gets sent to:
Nope. our normal cellphone number stands in all spaces.
Alrighty
let me chance the One Time Pin cell phone number under a separate option block at the top, not under personal info.
*clicks edit*
One Time PIN
We have just sent a unique One Time PIN to your cellphone number: *** *** 1394. (Not your number?)
This PIN helps to protect against fraudulent use of your account.
To continue with your transaction, please enter the PIN below.
So to change the otp cell number, i need the otp sent to that cell