FNB just decided to cancel my card while all I wanted was to dispute a transaction

I received a notification for a transaction I did not recognize on my account so I logged onto the FNB app to dispute the transaction. Went through the different screens to register the dispute, and at the end to my surprise I am told that my card has been canceled and Ijqve to order a new one. At no point during the process was i told that my card was going to be canceled, because I wouldn't have gone through it if I knew that. Now I have to pay to get the card replaced that FNB decided to cancel without my consent, replacement that will even cost me more than the transaction I was disputing. Pathetic. Wish I could rate them in minus stars. Why would you cancel my card just like that, FNB is just getting worse by the day.