[Resolved]  Nokia 5130 — automatic switch off/on proplem

i bought a 5130 nokia model about 6 months ago.from the very starting it was showing some problems.it was taking much time in switching off/on.but since that was not a major problem i just ignored it.
but now from some days it get switched off at its on in every 3-4 minutes & then start by itself.i went to nokia care to get solution but instead they vanished all stored data without informing me.they don't even told me what they are going to do.
i waited for about 1 & 1/2 hours & at last got my phone losing all data.as i step out i found that problem was still same.my phone was getting switched off again.means my 1/2 an hour waiting was just a waste.
i stepped in nokia care again & informed them again.they took the mobile & returned it back after installing some software saying that the problem is resolved.as i stepped out i found my phone was switched off again instead of having fully charged.
i returned back to home as i know it was senseless to go to nokia care & expect any help.now i really want to ask what should i do next?