Non submission of c forms

Hii all

I have a query regarding non submission of c form

A partnership firm made a interstate sale against c form in 2011 but didn't receive c form from buyer now sales tax department raised a notice for payment.

My question is

1. Now that partnership firm is not in existence so do the demand raised by department is valid??

2.Even after Gst will those non submission of c forms cases prevail and whether sales tax department  can raise demand in this case??

Reply me fast plzzzz