Airtel — internet data pack

Address:

Surat, Gujarat, 395004

Dear sir, i was vodafone customer till aug-17.
In aug-17 end i got call from some airtel office and they informed me about the airtel plan of 399. They informed that you will get 24 gb (4g) internet and unlimited calls. I got impressed and desided for mnp.
After mnp i used 4g internet for almost 4 days and then internet was not working properly. I thought it might be due to network issue. Today when i called customer care in airtel, first they informed me that you will get 4 gb + 20 gb internet from 5th oct-17 onwards, and when i asked them for cary forward my last moths 20 gb balanced they denied. Not only that when i asked to talk with they manager she simply replied me that this number is not airtel, you can visit nearest airtel store.
Just beside my shop the is airtel store (In katargam, surat, 395004). I explained the story and he rudely said you contact the person who called you for mnp for your lost 20 gb last month data pack. We cant do anything.
Its one month passed and i dont have that number who called me. How can i contact him?
My only request to airtel was to carry forward my lost 20 gb internet data whit i didn't used due to their mistake.
My airtel no. Is [protected].
Hope for the positive response.