Just a few easy steps.
1. TYPE *118#, then CALL.
2. Choose 6, The Cube. reply.
3. Choose 1, Musicube. reply.
4. Choose 6, Manage My CMT, reply.
5. Choose 1, View/ Delete CMY, reply.
6. Choose 1, Delete/Unsubcribe. reply.
7. Choose 1, Comfirm. Reply.
Wait until you receive a confirmation sms from Celcom. Like this :
Note: Steps/numbers may change time to time.
I tried this on 4.6.2014. 2:34PM.