Nokia N - 73 (Music Edition) — Memory Card got Locked after getting cell formatted and complete initial format also not available

Sir,
I purchased Nokia N-73 on 28 Aug'07. After only a month, it started giving problem of automatic switch off. After some days it also started showing the message 'Insert SIM Card' even though it received calls at the same time. On 20th Dec'07, I went to Nokia Care, G-Block, Vikas Puri. I got the cell back on 22nd Dec n when i switched on the cell n inserted my sim n memory card back in it, it is showing a "memory card Lock" and the initial format that it had is also a bit different.
Please Help.