I believe you are talking about RFA or radio frequency ablation. As I wrote, I had no long term relief but only an hour as one level at a time wore off.
I your case, stop listening to the doctors to pursue other procedures to help others properly diagnose the root cause of pain.
I did this on vehicles, as the complaint is info, what was done by someone else was also valuable info. Having an epidural at the affected levels can provide relief and/or info. Most likely images are on file that show perfect spacing, slipped disc forward, or narrowing.
If narrowing space between the disc over three years (1 yr to start, 2nd yr to hurt, 3rd yr to pursue surgical help. An RFA is least intrusive, but a lumbar fusion using the brackets, bars and screws (Called Harrington Procedure/ Found on YouTube/ I have one with photos) but perhaps one night stay but I can tell you one thing. Depending on the type of injury or trauma you had, the longer you take to get it properly diagnosed to the current root cause, the longer it takes for the nerves to heal and pain to stop. All intrusions into the body create scar tissue. Only scar tissue in the knees & elbows are violently fixed, to a degree. A muscle is thousands of flexible cells that can expand & contract. Once torn, they leak, grow together and become solid. Don't wait! Research, nail your Dr. to the wall or fire them. But go in educated. Know your options! Coming here to have a car mechanic of 40+ years tell you how to fix your back pain sounds crazy. Yet information, options, procedures your Dr. may not do are all important. Never engage in a battle of wits with an un-arm person, it makes you the winner.