Can my company force me to hand over my company provided SIM card for another user to use - after I leave the company ?

I thought that SIM cards were unique and were destroyed after use ??

What concerns me is the confidential data held on the SIM plus what happens if someone tries to contact me on it - after a new user starts using it ?

Don't know if its legal but when I was made redundant a couple of years ago I was asked for my Company phone before I went on gardening leave so that they could swop the SIM out - they claimed it was to protect Company confidentiality as I had suppliers and customers details on it. The Production Director then installed it in a spare phone and promised me that he would pass on my new number to any "personal" callers.They gave me the phone back for the notice period with a new blank SIM but made it clear that the phone was not to be used for outgoing personal calls.