I felt threatened by an employee and cancelled my reservation after calling customer service. In all fairness employee was alone cleaning a previously returned car, garage door open so I went in. No note on office door that they were closed and employee was sole person on site. I knocked strongly on window and door frame of passenger side, called out, went around side repeating loud noises, rapping and finally lightly touched employee's shoulder-this employee was vacuuming with head phones and totally unaware of any external movement, noise, customer which in retrospect I feel puts themselves is possible danger. Employee reacted with a start, pointed finger close to my face demanding I leave the premises. I had previously tried to contact Avis to extend reservation but only received robot calling which was impossible to accommodate me. It is a terrible system when one needs a person to help and there is no answer even during afternoon. I was a bit shaken and choose not to rent from Avis in any near future. Neither customer service or Kayak due to mechanical answering machines cannot provide service in such a situation.