lost phone that cannot be bkacklisted

<p> have a contract with Cell C, i Took a Data contract including a Samsung Tab E Tablet, unfortunately early hours of the 31st December my tabket was ******, i called Cell C to blacklist my phone so that the culprit could not use it, to my surprise they told me the want and EMI numebr , if i dont orovude it they cannot block the phone, when ask the reason for that they said , the last date my phone was in use dont correspond with their dates, i explained that it makes sense because maybe the person who stole it was using it after me, they said for that reason they cannot block it ,what if they block the wrong devise, it doesnt make sense to me because i gave then all my details e.g. ID numbers , bank account , residential adress, why cant they pick it up on their system which device iam paying for, now the culprit is going to continue using my ohone while i am paying for something i do not have</p>