You should give the shop that painted it incorrectly a chance to correct the issue.
Without allowing them to correct the work that you are unsatisfied with, you can sue all day long and you didn't do your duty to mitigate damages. If they told you that they would not attempt to fix it, that's a different story.
Give them the opportunity to do the right thing and make your expectations clear.
If then it doesn't work out, pursue other alternatives.