Tempest Europ Car not returning deposit

Rented a vehicle on the 27th of June. Returned the vehicle on the 4th of July. They claim there was a spare wheel when the vehicle left the lot and insisted that I sign an acknowledgement of liability. Eventually I did. They sent me a statement indicating that they owe me my deposit (minus some arbitrary fees). Then the harassment from Europcar started that I must pay the super waiver co-payment or else......which I did on the 16th of July. I have already in the meantime, queried 3 times about my deposit. Twice they indicated that as soon as they have processed my POP, they will release the deposit. It is now the 1st of August already!!!!. Currently they are ignoring my most recent query.