How to repair a broken spring on couch, the seat is sagging.?

Our sofa sags at middle cushion. I tipped couch over and one spring was broken and the other came loose. I wrapped wire around broken spring and around the wood it was attached to, the second spring I reattached and wrapped wire around to hold together. Now it’s back to sagging again!  Is there a better - more permanent way I can repair this? 

Yonatan2428 days ago

Perhaps this could help?:

https://www.youtube.com/watch?v=ptVY5sCNWpI

Only by replacing the worn out springs and attaching them properly.
Sometimes you can be lucky to get these springs quite cheap at upholstery companies, especially those specialising in furniture and car seat repairs.