remove the hold please

On the 10th of last month I was travelling to Durban. Got there at 13h00, went to thrifty car rental to rent a car, card kept on declining that's when we learned that two amounts - R2000 and R5000 on my card had holds placed on them. That's when my nightmare started, was sent from pillar to post and finally spoke to Wanda Sethemane [Email Removed] who knew what the problem was and how to fix it, he asked thrifty people to email him an authorisation to remove the hold, hold was removed however only on the R5000, another email was sent to him last week and no feedback received till today. Today a Thembenkosi claimed to have no one by the name of Wanda working there and no one knows how to assist. Please help.