Is it normal to have shifting in my teeth after only having veneers for a few months?

I had 10 veneers put in on my top teeth, of which one is moving backward creating a big gap and making a noticeable ridge (from veneer to veneer) that would normally be smooth behind my teeth. I called and the Dentist told me I would like need invisaline to fix it. Why I would be charged for invisaline when the shift must have occured because of the veneers. I have not had shifting issues in 15 years since having braces. Also my molars have been out since for about the same amount of time.