Product: Debt collection

I was contacted by Bushwood Capital Group a few weeks ago and made multiple attempts to call back and discuss. For a while there, I never got an answer to my phone call. When I finally did get an answer the woman on the other end was very abusive with her language and told me that she had already talked to another representative of my company and she would no longer need to talk to me either. Even though I am the correct person to talk to. She claimed that she was told by my company we would be hiring an attorney and it was out of my hands. She told me she has talked to multiple trucking companies in my area about me and she knows how the billing process works out here. She told me she had talked to multiple companies that also claim to owe me money so she " has a very good idea about the type of business we are running out here. '' She also said that when her client first contacted her they wanted her to go after all of my current clients and let them know what is going on. This, she said, would bankrupt us and put us out of business and that was what the client that originally contacted her wanted them to do specifically. She was not opposed to doing this either she said, and as I try to talk to her about it with patience and grace, she said she would only be talking to an attorney, making me feel like I have no choice but to hire one, which is wrong also. I then got an email from her with the subject line as " pre-litigation case '' and the documents in it were all hand written and do not take lease percentages into account. As we are on or near a XXXX XXXX XXXX, the percentages are a little harsher as well. Upon reading the email thoroughly, we are being charged an interest rate on this money that was never discussed with our original driver, and the collection agency is charging the XXXX dollars in fees to my company even though we did not hire them! 
After the phone call with her, I called the 1-800 number for their business and I got a male that said he was the manager. I tried to explain to him what happened and how the woman wouldn't even talk to me. He was nice to me until he got my account pulled up and them he shut down just like she did. He told me all the money was due in full and fees and interest was on my company to come up with, ( almost doubling the amount that was way off to begin with ). He also said we had three months to pay and then we would be in trouble. They have thrown random names out of people that we know personally that have nothing to do with this matter and I tried to ask him about this and he shut down even further. He kept trying to turn the whole conversation around on me like I was doing something wrong. I got off the phone with both of them shaking and crying, The male also threatened me that I could no longer approach their client and work things out between ourselves, which I still want to do. 
Other than a hand written claim as to what we owe, I have never been mailed or emailed anything else and I am at a loss what to do with a company that is willing to treat me this badly. 
Also, our driver was in our safety program receiving all the oilfield benefits of that, and we have charged him the standard rate for that, something the collection agency was never told about I'm sure. We also got a steel cradle manufactured by a local welding shop that our driver kept and never returned and we also have to take that into financial consideration, along with the times he used our equipment, ( which would change the rates we were charging him ). 
With all of this taken into consideration, and the fact that the collection agency will not discuss any of it with me, I do not know how to move forward. With the fourth quarter slowing down and now COVID-19 I don't know how we will make it out alive and I hope for some help and kindness on this matter.