Merchant One Holding excessive funds (over $58000) received through credit card transactions without cause and charging incorrect processing fees Miami Beach Florida

On December 10th, they processed several credit card transactions for my company (sole owner). The clients were low risk - all had credit scores of 780 to 820 and the bills were paid promptly. 

They have held these funds (in excess of $58,000)  for almost 4 months without cause or explanation. Additionally, despite my contract stating that the transaction fee would be 1.55%, they have debited my account in excess of 3%!  No one answers the phone and no one responds to emails.

The last time I was able to speak with someone in customer service (after being on hold for hours over several days)they stated that someone in the "risk department" would be able to provide assistance, but they did not know their telephone number or email and would have to get back to me - which they have not.

Per BBB, Merchant One has repeatedly done this to multiple other companies as well!!!