Shoddy Service job

Hi , I booked my car in for a service on 3rd of July. After the service my car started making squeaking noises that it never was before. I've never experienced an issue like that because I always took my car directly to Suzuki dealerships for servicing. I had to take it back so they could check the car and their workshop staff did something weird to the car. Nonetheless, it's a week later and the car is still squeaking everytime I reverse. What did you guys do to my car? It's such an inconvenience because now I have to take it back yet again. Why I'm writing this complaint is because your team had the ***** to send my details to a sales person to try sell me a new car while your workshop did a shoddy job of servicing my car, it's hard to trust your branch. NUR18871