Trai — no dues - paid monthly bills till date but not activation permitted

Address:

Chennai, Tamil Nadu, 600015

I am the user of aircel and i have their sim no morethan 15 years. Due to their own problems aircel asked us to change the network providers.
I sent a request on 26th feb 18 and i got the port no. On 27/02/2018. Immediately i handover the same to airtel and they told me wait for a week
To-day i approached the airtel and they says that i have been kept with
Pending payment list and aircel will not permit till i pay their dues. I showed the sms recd on 09/03/2018 stating that they have received my last payment of
Rs. 722/- and their receipt no:ch98410461021520571904990 dt 09/03/18.
Infact they are holding my security deposit of rs. 3, 000/- for the last 15 years
And neither interest for this amount nor refunded to me. I am not able to understand when i am not due to them what made them to put it my name into the payment pending list.