I've just received an update text telling me that I have been awarded Mat Allowance but it's not the amount I was expecting at all, in fact it's half of the full entitlement which I earnt enough for in a 13 week test period on average. I started a new business in Jan last year (which was part of my test period) and it wasn't until the summer that I earnt enough for the full entitlement, I suspect that the NICs have something to do with it but I've always paid those fully despite not earning enough from my SE work to 'need' to and I was under the impression that I would be asked to pay the NICs from April 2018-April 2019 by HMRC before my claim was awarded (it says as much on the maternity allowance claim forms).
Is there anything I can do about this?