There have been a bunch of fines and sanctions imposed on the various leave campaigns but as far as I can tell they are mostly due to technical violations such as spending over the limits rather than the content of the messages.
That number in particular is grossly misleading but not an outright lie. £350 is a gross figure and doesn't account for the rebates or the money the EU was spending in the UK, not to mention the indirect benefits to the UK's economy.
In other words the UK was supposed to be paying £350 million per week but IIRC the net amount was closer to £150 and even that doesn't account for a variety of other considerations.
That number in particular is grossly misleading but not an outright lie. £350 is a gross figure and doesn't account for the rebates or the money the EU was spending in the UK, not to mention the indirect benefits to the UK's economy.
In other words the UK was supposed to be paying £350 million per week but IIRC the net amount was closer to £150 and even that doesn't account for a variety of other considerations.
Edit: fixed typo