Is Avis a ****?

I have been renting with Avis from September they had a monthly special, then last month October out of the bloom they changed their pricing for monthly rental I had to pay another deposit on top of another one (the September hold has never been paid back to my account), this month again they changed their pricing I had to pay another deposit on top of two deposits. Please help I really need this money paid to my account as soon as possible.