Airtel — 4g data and portability - cheated twice

I have been using my prepaid airtel sim for more than 6 years now. It has been almost 2 years since I have upgraded it to 4g.
For the past 4-5 months, I have been recharging using the 'My Airel' mobile application. The app offers me 28 days of free calls and 1GB 4G data per day for Rs.349.
I noticed that for other customers (my friends), there was a better offer of Rs.399 which offered 84/70 days free calls and 1GB 4G data per day.

Since this offer was not available for me in the app, I decided to port my number to Jio. To get the porting code, I had to send a text sms to aitel after which they sent me the code.

Within 1 hour of getting the porting code, I was contacted by an airtel representative by phone. The person informed me that I will get 90 days free calls and 1GB 4G data per day if I recharged for Rs.399 through the mobile app as this was a new offer given to me to STOP ME FROM PORTING TO JIO.

So, I went ahead and recharged my sim for Rs.399 through the same app. However, I did not get the above stated service. I received only 28 days of free calls and 1GB 4G data (which is same as the Rs.349 plan).
So, I incurred a loss of Rs.50 and had to use the same airtel sim for another 28 days because they called me and made recharge.

I contacted customer care (121) who were very irresponsible. They stated that I was called by the 'Portability Department' and it was not under their scope and that they had NO ACTION REGARDING MY SITUATION.

So, after a month or two, I tried to port again. I sent the text sms to airtel requesting for the portability code. The same thing happened.

The Portability Department called and said I would get 90 days free calls and 1GB 4G data per day if I recharged for Rs.399 - but this time not through the app or website, but from a recharge shop. The representative repeatedly assured me that this time, I would get the offer they promised.

However, the same thing happened again. I received only 28 days of free calls and 1GB 4G data (which is same as the Rs.349 plan). So, I incurred another Rs.50 loss. I once again called the airtel customer care who confirmed that they will not be able to help.

So this is how airtel conned me twice by making me pay Rs.399 for the Rs.349 plan. They also made sure that I stayed with their network and did not switch to Jio.

I require airtel to provide me the service I was promised. Thanks.