Atrocious Service Fro Mercedes-Benz

My Mercedes CLA has been giving me issues, including lag, high fuel consumption, & other electronic problems as well as a squeak coming from my front tyre.

I took it to Mercedes Sandown so may times for the same unresolved problems, to the point that they claimed to have imported parts, which didn't resolve the issue, until they eventually gave me a loan car, so they can ensure they resolve the issues.

My car was there for over a week, got it back yesterday & the squeaking issue is still there, which begs the question, if they worked on the car at all?

This is truly atrocious service from them, especially since I've got there premium service package, which cost an arm & a leg.

I've escalated this, which didn't make a difference. This is really unacceptable, when my car is more in the workshop than on the road driving :(