Company not return my cell phone

Location/place: Delhi

Name of company/service: Karbonn Mobile

Sir
My cell phone Model no.A1+,IMEI No.911123201665443 hai sir mera cell karbonn A1+ last 4 month se service centre par hi hai service centre wale kuch nahi karte lene jao to kehte hai sahi kar diya laykin wo sahi nahi karte.mey 4 month se bahut pareshan hun service centre ke chakkar kaat kaat ke sir plz mera cell replaced karwa do plz.service centre ka naam aur address hai:-

Suri Telecom
Contact Person: Praveen Sharma
Contact Number: 9811790455
Service Centre Contact No: 01132926923/9312131418
Address: 454/55, West Guru Angad Nagar, Laxmi Nagar-110092
Email id: [email protected]