Passcode not working

We did not send you anything. We are not Apple.

In addition, if you don't know the lock screen passcode, no one can re-set or change it remotely.

Your only option is to restore the device.

If you forgot the passcode for your iPhone, iPad, or iPod touch, or your device is disabled

Who sent you a Passcode? Apple does not send passcodes. Only the person who set up the code on the device directly could know it as it's stored on the device only.

Use the link KiltedTim provided.