Airtel — refund of security after changing portability

My mobile number is [protected]. I have availed portability of number in june2019.
I requested for refund of security. The company has informed they have sent a cheque on 28th june till 7th aug. I did not receive. Then i sent copy of cancelled cheque as per their request. I sent it. They mailed me that they paid it on line on 2nd aug. But till 7th it was not credited to my account. Now they require bank statement from 28th june to 7th aug.
How is it possible to send bank details to any body. I can get it verified to their outlet at paota jodhpur nearby to my house.
Now there is no response from airt
Dharam narain joshi
Jodhpur. Phone no. [protected]