My funds not released after rental

I rented a car from avis on 09/07/2015 and returned it on 21/07/2015, and still my funds are still frozen despite the fact that Avis has already debited more money from my account, i was told by the avis agent that my funds will be released after 6 days maximum but its been 3 weeks, this is bordering on theft by avis, i call customer care on Wednesday an they said the funds will be released in 48hrs, but still nothing.<br> <br> This is unacceptable, you are keeping people's money so you can earn interest on it before you return it. <br> <br> This is very disappointing from a company of your caliber.