When I brought my car there to replace the brake l...

When I brought my car there to replace the brake lamp, they said it would be $19. When I saw the actual invoice, it was $139.50 just for the parts. I realized this later and sent a message to them from my mobile, and then from their website. But it's been a week and no reply. If $19 was a mistake, that's fine, but I don't understand why they don't reply to my question. I even chatted with them through their website, and the operator promised to convey my message to the service depatment. I've been a customer there over 6 years but now getting frustrated every time I go there.