Unexpected 1,700+ CHF Invoice for 15-Minute Door Handle Repair—What Can I Do?

I had a balcony door handle repaired, and the company took 15 minutes to complete the repair. They used epoxy to glue the handle, and it works now.

I received an invoice for 1200.- When you asked for a detailed invoice, they raised it to 1724.- Swiss francs. The job involved gluing a handle for 15 minutes of work. Has anyone had a similar experience? What’s the best way to challenge or resolve this?

The name of the company is Alpen Glas GmbH, located in Freiburg.

Thank you in advance.