If you are not satisfied with the resolution provided, or it remains unaddressed or no intimation of redressal of the complaint is received within the specified period, you can approach the next tier - the Appellate Authority for Redressal. You will find the name and number of the appellate authority on the website of your service provider, and also on the booklet that you got when you bought the SIM card.
The appellate authority will also give you a specific time for resolution. However, keep note of time, complaint number etc for future references.
To know your rights, you can refer to the booklet that comes with the SIM card. One of the important points here is that service providers are obliged to keep a record of each and every complaint for at least three months so even in case you lost your SMSes or other details, the service provider will have the record and you can ask for it.
