Nokia India — Erased all the phone memory contents including my contacts and installed apps

Address:

Ernakulam, Kerala

My Nokia Lumia 520 screen was broken. Yesterday 23/02/15 I given the phone to to Nokai Care, Poovath International(Banerji Road), Ground Floor, Kurien Towers, Banerjee Road, Ernakulam, Kerala, India. I asked them to replace the screen and update the software to latest version. Screen was replaced, but they hadn't updated the software. When I asked, they updated the phone but all my phone memory was deleted (Contacts, installed apps etc). I know a simple software update will not delete the phone memory. They are not giving importance to customers data and value. For the apps I can re download again and reinstall it. But for the contacts what should I do? I have no idea and helpless. When I asked about this they are telling that it is usual when updating the software to new version. Please help me.