Why use Avis? Terrible Service

We rent a car on the 14 March 2015. Collected the car 9.30 arrange to return the car next day at Bloemfontein airport. So I was told they are going to withhold R5000 R1600 on my credit card and was told when I take back the Car I should authorise the release of the R5000 as they had problems over weekend's they also said the rest after the rental fee will gr released in 3 working days. So I returned the car requested the authorisation of the R5000 on wednesday nothing yet so I phoned the branch the guy in training said he will ask his manager to phone me back. Friday 5.30 he phoned giving me a call centre no to sort out my problem. When phoning the message I got open 8-5 Min - Fri, im sitting the whole weekend with a credit card I cant use with a hold of R6600 how many cards do they think one own. Its ridiculous if I have an emergency what should I do? They wont reimburse me for their neglects or my inconvenience will probably apologise via hallo peter and thats it it in the mean while im stuck the whole weekend. Thanks Avis your service is getting worst by the day my husband and I will definitely think twice before using or recommending you.