No help when needed

I have had an unpleasant experience dealing with KBS after moving out of the apartment I stayed in. They are the agents that took over after the flat I was renting was sold while I was living there. As the new agents I expected them to sort all the money transfers and agreements with the previous agents out. Instead I have had to figure out which agents have my key deposit myself, I have no idea how I am expected to do that if I have no documentation of what was shared between the 2 agencies, none will send proof of the monies transferred but I'm expected to sort it out myself, I have asked KBS on countless occasions to assist with some documentation but I was given empty promises. On top of that there is an issue regarding a gate tag they are in possession of which I paid for. I am just trying to get a refund, I have sent them all the documents they required and followed up countless times but they have resorted to ignoring my emails. All I need is assistance but I have not been able to get any.