Institute - Customer care service retailer

customer service office in ambattur near canara bank
yesterday i went to complain about my airtel sim not working issue, in that branch, so the customer service person Mr.Saravanan said that your sim is not working so you have to change to new sim to this same number but he ask Rs **, so for that i ask why i have to pay he told me that for new sim you have to pay, and i also ask Ms.Geethanjali head of that branch she also said the same in a rough manner "you have to pay else get out " you may complain any where i dont boughter about that, then i pay rs ** for that and i came, but in my mobile i received a mess that your sim change request for mobile number ********** is completed. retailer would have charged you rs ** /- as service charge for sim change
so I need the reason for that why i have to pay rs ** the new sim, and also no respect in that particular airtel service center retailer Head as well as working person so please take necessary action and give the valuable feedback
Thanks & regards