Multiple unshown chargebacks (as claimed by support)

 I recently had an issue with multiple charges being made when trying to purchase BFC in BF6. Long story short, they were refunded. Then, I made a purchase of more, that should have left me at a positive 5000. Now they have me at a -2400. After contacting support, they claimed that charge backs were made for some orders. They never told me what order numbers they were even when giving them any and all transaction numbers for the last month. They were claiming there was transactions on dates that no transactions were made. I have contacted all my card providers with no shown chargebacks. 

I want to know why. Support has refused to help on this matter and even told me to make a post here.