Case: After 8 months I purchased a new piano, my piano has been tuned 4 times: 2 times by the branch store and 2 times by the manufacturer's headquarter. But I was not satisfied with the sound, so I requested another service for tuning. This time I were told that I would have to pay for the service. I think that it is not fair for me to pay anything for the tuning service because the warranty period is still valid.

Resolution: Tuning a piano means controlling the tuning pins on the top part of the piano to set each key's string to certain musical frequency. One piano has about 200-240 strings, and each string's average tension is 90kg, so total strings' tension is over 20tons. Therefore, this powerful tension of strings pull the tuning pins constantly, and the piano gets out of tune regardless someone plays it or not. The temperature and humidity of the room where the piano is located also affect the piano's tunes. Pursuant to the Regulations of the Damage Compensations for Customers, 2 times of free tuning service can be given during the warranty period, and customers should pay for tuning service after the warranty period is over.

In your case, since you already have received more than twice of the free tuning service, no more free tuning service can be given to you.