I had changed the plan and now Airtel app is showing previous data, new data, old plan data and more. When I use data it gets reduced from previous data, but customer care ask not to use data from previous data, but only from current plan. They said their systems won't work correctly until my next month bill cycle and hence I need to calculate my usage manually. 

Apart from this, I also get message telling about surprise offer, but without any such offer. I think they are just trying to catch up with Jio announcing offers which their systems cannot support. I think it is better to PORT out to avoid a huge bill in next cycle. Customer care explained all these and said they will email, but looks like the email is coming through the Bangalore traffic (has not reached in hours).

Also, read the text 63.5GB available of 60.5GB. 16.1 GB available of 13.1GB. What is happening Airtel? 

We have forwarded this to customer care email as well as facebook and twitter. Hope they will reply back.

Updates

They did not reply back. But when I called again, they raised a complaint and said all data will be removed. I think it is better than having data which should not be used.

In response to PORT request they restored the monsoon surprise offer too (updated the pic which now has 13.1 GB).

Interistingly all data was carried forwarded. So marking the issue as RESOLVED.