Botox Injections for Migraines

Has anyone else had this done? About a month ago at the recommendation of my pain management doctor, I had this procedure done. It took a while for all the approvals to come in from my insurance company but they did finally approve it.

My neck muscles are like concrete cylinders and my trap muscles in my shoulders are the same so the theory was to inject them with a ton of botox and three weeks later, they would loosen up and the migraines would calm down.

Well the muscles did loosen up for about a week. going from a concrete scale of 10 down to a 6 but now after one week of a 6 of looseness, they are back to a concrete scale of 10. Is there no hope for my neck muscles? I get massages and apply heat therapy. I even use the tens electronic machine every third day.

Any advise is appreciated.