Investigators are falling to do their job

Can David be removed from my case as he totally don't know what he is doing. I say that because I have sent more than enough complains and he is failing to resolve my case. He is always making unnecessary excuses which is unprofessional and waste of time. First excuse he asked me to send him a phone bill of the cellphone that I made a call from to report my card which I explained why I cant send him the phone bill but he never bothered to call back to tell me what's going on and when he call after i send another complain he tells me that he is still waiting for me to send him a phone bill which he knows that I cant. Next excuse he tells me that he will send me a letter which he is going to send to the ombudsman which he never did until I send another complain he then call's and make another excuse that he is waiting for the letter. I believe if I don't send a complain David can never call me to let me know what is happening. David he is *********** and lazy, Please get me someone professional who can help me. <br>