How can I help with this please?
It really doesn't make much difference.
You can write to them putting them on notice of your name change. However, there is no point in challenging this on that basis.
There is case law on what makes a summons defective and it literally has to be such that you couldn't understand it was for you. There is no doubt to whom this was addressed. You recognise the name and know it relates to you. That is not a defective summons.
Sorry if that is bad news.
Can I clarify anything for you?