My stan char lifetime free credit card got discontinued because of non spends. How to get it back?

[NikhilG]

I guess they reached out to me via text msgs but I didn't realize that I had to give a missed call in order to let them know that I wanted to continue using the credit card. Is there any way I can ask them to undo the discontinuation of credit card or I need to make fresh application. If fresh application needs to be done do I need to wait for sometime?
Also can I participate in cashkaro reward schemes which gives gift card for ntb cc applications?