Lost my messages and phone numbers

my brother mistakenly did a back up restoration on my nokia 5130 xpress and he swicthed off the phone before the process was completed. i tried to do another back up restoration and i lost all my contacts and messages. the week i bought my phone i did a back up just in case i may need such information.but now with the recently made back up messages that are appearing in my inbox are from the 1st back up which i had done 4 months ago. all new and recent sms and my phone book has disappeared. what do i do