They are fucking you ask to speak with service manager and show him pics. Also write the vw regional office and tell them 3 other dependable capable shops agree caliper is bad. If the problem isn't fixed you will take it to another dealer for all further service wor

a 200$ caliper is worth fixing if you threaten to take it elsewhere

plus no pad should ever wear that unevenly ask them to tell you why it does that explain how that is "normal"