Hooter not working airbag light on

The installation guy came to install the tracking device on my VW T6 Kombi and since then my hooter stopped working and the airbag light is on. I’ve waited for almost 2 months for the technician to come fix the problem but the problem still persist being sent from one pillar to post. I’ve been driving a car with both the hooter and airbag not working. This is the worst service I’ve ever received.