Poor service from Avis customer care

On March 30th I took a car from Avis and they held the rental deposit and a safety/security deposit. On April 2nd I returned the car, a few days later the invoice was sent through and the car deposit was released, however, the safety/security wasn't released. I sent an email which was responded to days later and they said it'll be released back to me within 1-2 business working days. 20days later my deposit is still pending, customer care is no longer responding to my emails. The 086 number drops the minute I choose option 4 for customer care. The PTA downtown branch never answer their phone. Luckily one day I got through to the branch and spoke to a lady to first wanted to refer me to customer care and I refused, then she said she'll send them an email and copy me so I can see their response. To this day no such has happened and the deposit is still pending and no one has a reason why.