Sony India — sony audio system

Address:

Vadodara, Gujarat

Since my sony audio system was malfunctioning, i went to your balaji services, akota, vadodara and showed it to them. They accepted the same and told me that they would text me the repair charges after checking the system. On 12th morning, at 10.34 am, i got a message stating the amount for repair. Then they called me and asked me to send them an ok message if i was ok with the amount. I sent the same.
Then the same day, around 1.31 pm, i received another message stating another amount, followed by a call saying that their first amount was erroneous. I said ok and also sent another ok message to them.
Then again on 17th sep'18, i got a call from them saying that they need the cash memo for the system to carry out the repair.
Not sure why your staff is asking for things from customer in instalments. Can they not ask at one go whatever is required to enable them to carry out the repair?