It is my understanding that the IRS classifies a stylist that rents a booth in a salon as an Independent Contractor.  To me that means that you bring with you all the tools of the trade but you have rental rights to use certain equipement  - such as hair washing stations and water - that are included in the price of the rental agreement.  You need to see if the rental agreement addressed the issue of the machine and if you agreed to what was going on. If you did not agree then you may be able to have your own terminal for sales.   It really looks like they are treating you as an employee rather than an independent renter.  Good luck.