Disappointed with your refund process

Am really frustrated by ticketpro client service I have been begging for a refund for a double debit on my account.. I purchased tickets for the tamia concert and they took double the money but can't account for the second transaction they keep saying their finance can't see it even though it's reflecting on my statement. They ignore my emails I call they say they will call me back but they don't do that I went to my bank and my bank said they can Assist me but they need a letter from ticket pro with a letterhead stating that they did not receive my second transaction but still they going back and forth they can't do a simple thing of sending me the letter so I can get my money back, I have all the names of the agents I spoke to and non of them were helpful like you guys are not fair Coz Now you making me beg for my money you say you need to investigate I don't know what are you investigating because you said you can't see the other transaction am really heartbroken and I regret buying tickets from you coz Now Am falling back on my bills because you decided to take my money and don't give a **** about it I have called you more than 100times for the past 2days is this fair though?