I had used airtel for 4 months consecutively. I faced many problems throughtout this time with airtel network.
First of all, the network provided by airtel is very bad and doesn't works in most localities. Neither can I do voice calls nor I can use internet of airtel. The signal strength is so low of airtel. Not at all clear voice quality.
Customer service is also not that good. I requested some information of my airtel account on airtel customer care and they took 3-4 working days to get my request completed.
The charges of airtel services are so high. Earlier I used to buy 399 packs but now they made it so costly. I can't afford their unlimited packs for 3 months. The data pack prices are not at all reasonable according to the network they provide.
I switched my network and don't recommend you to use airtel.