Sears Carpet Cleaning & Air Duct Cleaning

I used Sears for the carpet cleaning deal of 2 rooms and a hallway for $ 85. My roommate was home at the time (I was at work), and I left him my credit card to pay for the service. When I came home the bill was $ 135, and there was a charge written on the invoice for an extra $ 50. It was very sloppy writing and I couldn’t read it, so I called to see what the extra charge was for. Apparently it was an enzyme treatment. The carpet techs had apparently told my roommate, «You’re going to need an enzyme deodorizer.» To which my roommate replied, «Okay.» The tech did not explain there would be an extra $ 50 charge for the treatment. When I called to find out what happened, the manager (I think her name was Hannah, that is what’s written on the invoice at least) was at first polite and helpful, but when I told her no one had explained the enzyme would cost extra she became very defensive and said, «My techs would NEVER do that.» I then handed the phone to my roommate so he could explain what happened, and I could hear her literally yelling at him and being extremely nasty and rude. They ended up getting into a screaming match on the phone and hanging up.
The truth is, if the tech had explained I needed the extra treatment and that it would be an extra $ 50, I probably would have agreed to it. It is the principle that it was NOT explained to me or my roommate, and it was shocking and disturbing that the customer service lady was so extremely venomous and unprofessional. I will not be using Sears for anything involving customer service in the future. I hope whoever that lady is gets removed from her position. She should not be allowed to interact with customers.