I have rented a flute for my son who was just starting out. The charges started immediately, although the flute only arrived a week later. His teacher then pointed out a few problems. I asked at the band I attend if anyone knew about flutes, and found a woodwind repairer, who sorted it out.
I did not contact the company, as sending an instrument back would have taken MUCH longer. Overall since all has gone well, and happy with the instrument.