Key blade in fob not working c4 Picasso

[Czam]

Hi I bought a secondhand 2017 c4 Picasso from a dealer 2yrs ago and recently the battery went in the key fob. I tried to used the physical key blade that is inside the fob and it inserted in the lock and turned but the lock didn’t activate. I tried the passenger side too and nothing. I tried putting it in upside down too. I drove home and got the second fob and tried the key blade in that and that doesn’t work either. Have they somehow given me the wrong key blades in fobs that are programmed to open my car? Or could it be another problem?

[Paul-R]

It's possible that the ignition lock and various other items (BSI and engine ECU I think) have been changed with a set off another car, maybe when something went wrong. It's also possible that the tumblers in the key barrels themselves have seized up due to lack of use.

[moizeau]

If you're referring to the door lock and it just spins, but some light oil in the lock (WD) and work the key a few times.

[Paul-R]

I read the original post as the OP tried to turn the ley but nothing happened i.e. they wouldn't turn. Perhaps the OP could clarify this?