I am paying Cambece Law Office in Beverly, MA for

You either missed a payment or stopped paying altogether....or your payment amount is too low (below $50.00).  Square Two has a multitude of "franchise" agencies / law firms that collect their accounts for them.  Simply contact Michael Scott, make sure that you update your info with them and continue with the payment plan.  They will have the date and amount of your last payment on their system (all franchises share the same software and can also see the previous notes from the previous agencies).  Good luck!

Seems like Cambece sold your account to Michael J. Scott. It does happen. But as I asked, did you request validation/check your credit report before you started working with Cambece?

Well, I was just informed by Aaron Cox with Cambece Law Firm that they no longer had my account. I have been sending payments the last 4 months, just sending out number 5 this morning. He told me that I needed to contact Square Two Financial and they could direct me to the office I need to be dealing with. I received no notification that my account had been cancelled with Cambece, and now I don't know what to do. Any ideas?

Contact Cambece and inform them about what has happened. See, what they tell you. 

Ask Michael J. Scott to validate the debt in writing via certified mail with a return receipt request. If they don’t give you a valid proof, then send them a Cease and Desist letter.
 

Do you have anything in writing from Cambece regarding the repayment of the debt? If you do, dispute the debt in writing with Michael J. Scott and attach a copy of the document with the letter. Did you validate the debt/check your credit report before you started paying Cambece?