Business ProfileforKlingback, LLC

I purchased a Keurig K15 coffee maker at ******** who offers these through Klingback LLC company, a third party seller, as I by now have learned.We used the machine for 3 days and did not like how long it took to get a cup of coffee. I brought the machine to our local ******** for a return. The ******* associate took the machine out of its box to compare it with the purchase information. The associate then put the open box into the back of her and proceeded with my return on her computer screen. She told me that ******* would ship this machine back and I will get a refund from this third party seller, Klingback llc.Today, I received a very troubling e mail from Klingback llc, saying they know I must have switched this machine, because they fan tell it was used and the serial number was changed. They also wrote that they now would contact my local law enforcement. For what?Unbelievably rude and ridiculous UT perhaps this is how this company refuses to accept returns? I am outraged. I brought the item I purchased ba k to ******* and in its original box and the ******* associate also checked the contents and condition.The return reason was given as not liking how slow the machine was. Perhaps that was a defect ? We are not coffee machine technicians, so we do not know if it was a defect or if this machine is just very slow. The water flow was vetu slow and we did not know that the entire machine was made of this shiny plastic, which shows finger prints and tiny scratches right away.We paid $299 before taxes for this machine and Klingback llc is obviously trying to get out of having to return this machine.What else fan we do to prevent this company from doing this to customers and what is *******'s position in all this?