Be careful when renting a vehicle from First Car Rental

After 2 weeks of renting a vehicle from First Car Rental and returning the vehicle in good order they authorise a hold on my funds for now reason???

The initial hold was R3500 which was released. Now after 2 weeks another R3500 was authorised to be blocked, and then again a few hours later. They have now blocked R7000 of funds for now reason at all.

After contacting them I don't get any reasonable explanation except for the funds would be released soon.

I have canceled my card and reported it to the ***** department...

Will First Car Rental pay for the ordering of my new card? I would expect an apology and repayment.