Lazy air vents

[M16UEL]

Hi all new to the site, just purchased a 14plate b class sport as we had the previous model so thought we would stick with what we know, however this newer model seems to have a few issues, the heater vents seem to work when they want know matter what setting you choose does anyone know if this is normal or is the main dealer fobbing us off

 

[Giantvanman]

Not wanting to teach you how to suck eggs……..
Is your car fitted with climate control because this may explain why it turns on/off when it feels like or more accurately, when it senses temperature change different to what you have set?