I haven't had RFA/ radio frequency nerve ablation done, but do know that it is not uncommon for pain to increase dramatically in other areas after it is done and last for several weeks.
Usually muscle relaxers and pain meds are provided afterwards to ease this pain until the nerves start to calm down.
Was your steroid injection done under floroscopy so that the doctor could see that it was being injected in the correct location?
It also isn't uncommon for pain to increase for several days after a steroid injection is given into the spine.
You should call your doctor and let him/her know how much increased pain you are in since having both the injections and the RFA.
Good luck
Fran