miraculous deletion of all contacts

hey guys,

i recently got an sms with a contact person in it. when attempting to open the contact, the contact application crashed, and then no other applicatio would open, not the phone, not safari , not native app i have downloaded... seemed the phone was crashing. i thought, i will turn the phone off and back on. when doing so, i noticed all of my contacts have been lost. the weird thing is that when going to my favorite, the names were still there, and then when leaving the favorites and coming back, they were just the numbers that were saved. when going to whatsapp, all the names were there, and when clicking on the contacts, all of a sudden they were lost from whatsapp as well. the phone is not jail broken, i havent backed up my things in months. my phone has been turned off and back on several times since my last connection to itunes. i tried a hard reboot (holding home and power button for 10 seconds)... still no contacts. 😟

any suggestions?