Hello, I just had a customer return a racquet for restriging and just wandering whether I should charge the customer as the string has broken in an unusual place. I strung the customers racquet last time. It is a Prince Precision Reponse Titanium Midplus. Strung with Wilson Ultra Synthetic Gut 16 gauge. String broke on the 4th to 5th right main at the grommet and thinking it may be a kink last time I strung it. I haven't strung the racuet for several months at least and he is a club player. Any advice would be great please.