Bst way of cancelling a contract?

[Diesal]

So my contract expires in May!

How would I go about cancelling it before it is renewed on the month to month basis?

So glad I'm leaving because, the quality of MTN's network really stood out when load shedding took place and I was forced to use a almost constant edge connection.

 

[ZolTang]

Mine just ended yesterday... Went to the shop out of paranoia. Cancelled it there and then and went over to pre paid.
Now I cant connect to the internet FML!