Should I Be Concerned? 2 Weeks Post and Have Welts/Lines?

I got Ultherapy 2 weeks ago. I had over a dozen welts/lines on both sides with tiny blisters and scabbing. I also looked like a chipmunk with all the swelling. The swelling has gone down but I can still see and feel the lines. They have lightened but are still very noticeable. I went back to the office I had it done after 3 days and they reassured me it was normal and would be fine in 7 to 10 days. After 7 days I called and they said to put Retin A on the wounds to help them heal faster.