SIAM has the ability to suspend a SIM card. Suspending a SIM stops the SIM card from authenticating on a network, however you will still be charged the Service Charge.
To suspend multiple SIM cards see: How to bulk suspend SIM cards.
To terminate a SIM card (terminating a SIM stops the SIM card from authenticating on a network, and will incur cancellation costs if the SIM is still in contract) see, How to terminate a SIM card or How to bulk terminate SIM cards.
This is found at SIMS > SIMs List > Action > :
If successful the SIM Network Settings will appear:
If successful the SIM change state form will appear:
If successful the following message will appear: