Lenovo — poor service centre in haldwani

I had given my phone at your service centre in haldwani and when i got my phone back i found the sim tray was missing and when i tried to enquire them about the sim tray they said it is your fault and we don't have any sim tray and moreover the way of talking was very bad. I had such poor experience at your service centre in haldwani and i will never recommend to buy lenovo phone to my friends and everyone. It is very very very very bad service centre. I want you to take some action against them.