Barclays offer me £300.00

Bmth100

You didn't even know that this had happened, so I think you should take your unexpected £300 and pat yourself on the back, providing they have sorted out whatever they ballsed up.

Have you actually tried to apply for - and be rejected for - any credit recently that you could attribute to Barclays affecting your credit file negatively? Even if you have, £300 is very reasonable.

I deal with the same situations at work. When judging fair compensation amounts, we use past Ombudsman outcomes to help make s judgement. What you have been offered will most likely be deemed fair by the FCA even if you try to take it further.