I'm using postpaid and my simcard number is 896001150325962363(2) as stated on the back of my simcard.

Hi hambalibashah,

Have you tried the self-serve menu from your phone? You can dial *131#, then select 'Subscription Check' and proceed to unsubscribe from the menu.

Thank you.

Done Unsubscribing. Basically I had to dial *131# > 5. Manage CRT > 1. CRT DIY Package > 4. Delete Package. Thank you Maxis for your prompt reply.