[TEE10]

Hi all had an old sony ericsson satio u1i fon it says INSERT SIM
so i took it to get unlocked cost £10
he said its unlocked but wen i put an ee sim it says the same INSERT SIM
shop bloke said sim reader damaged
but wen i put tmobile sim it says registration failed but it lets me in the fon
so i'm thinking he has not unlocked it
if the sim reader was damaged it would not say sim registration failed at all
sim registration failed only says that because the tmobile sim is an old unactive sim
have i got to reflash it all is there another way round it
and if so what files or software do i need to reflash it
any help much appreciated
thk