Can I sue the dental clinic?

I had braces years ago and have been replacing my permanent retainer every year. My permanent retainer broke a few months ago, so I had a new set of permanent retainers made and attached at a new dental clinic (Having moved away). The new ones broke off a month later and I had the same one re-cemented for free (obv). Two months later, I noticed a lot of gap in my teeth and headed back to the dentist. It turns out my retainer had become loose again, I got a removable retainer done for free, but now my teeth look as though they never had braces. The clinic refuses to compensate for the damage done by their poor treatment because it has recently been take over by someone else. What do I do? All that money spent on years of treatment looks washed away.