Misled by mobile service centre

My daughter submitted her Samsung Galaxy A8 phone for repair at a Samsung service centre in Delhi. Earlier they promised repair out of warranty against payment of 7500 but a day later the employee called to inform that the damaged part isn't in stock and hence they will refund the amount I paid to buy the phone minus the repair charges and asked me to submit various bills and accessories to them as soon as possible. They called her everyday for at least three days n finally asked her to mail them details incase she wasn't able to visit the store. She mailed all documents and they confirmed they have received all documents and they are appropriate and are sending the request to company for approval. As she is a doctor it's imperative to have a phone n hence we purchased a new one. However five days later they call her saying they have repaired the phone . They didn't inform that repair was still in process and just talked of refund. We feel totally misled and harassed . And are demanding relief of repair charges and want to file a lawsuit in consumer court but they aren't even ready to tell as to who out of the company or the particular service centre franchise is responsible for this and against whom the legal proceedings have to be done. Kindly guide if we have the right to obtain this information and how can we pressurise them for the information.