k550i memory stick(M2) error

I recently purchased a sony k550i ,and purchased a 1 GB memory card ,along with it .The combination worked well for 25 days.

However yesterday ,after my sister clicked some photos ,i decided to transfer it to blue tooth ,as i went to my bluetooth menu and reached till themes menu , suddenly the screen got white and the mobile automatically switched off .When i restarted it gave a message that " do you want to format the memory card " .I ignored it but i found that at every possible place (Camera,file system etc) it showed that memory stick is not available . When i connected it with my PC via USB the phone memory worked well but the memory card gave a format error .However i was unable to format the card as no format(fat16,32 etc) was possible.I formated it in my phone at startup promt but it showed unaviliable in usable areas and problem persist.

To check whether the phone has malfunctioned ,i inserted the 128 memory card which came bundled with it ,and it worked well .

What should i do ? I purchased the card for 1k and it has a sony brand marked behind it so i can't say whether it is duplicate or not.

Looks like a fake memory card. Do not format the card via PC. You need to format is on phone. But can't say how long the combo will work without problems.

Always buy genuine products even if they are a bit costly. The genuine ones come with a 3year (or 5 year, I don't remember correctly) warranty.

Take back card to the shop...and ask for replacement as it is only 1 month old.

Same thing happened to me. I bought a 2gb M2 for 1.6k which i knew was fake. It just worked for one day. And the same problem as your happened. So i went to the shop and replaced it with a 1gb original for 1.3k. The fake one had Sony brand name and its nearly impossible to distinguish the fake from the real. But originals always come in a sealed pack and with a 5 year warranty.