Tax repayment in error

I have just received a cheque for overpaid tax but this payment was already made to me last year. I've logged into my SA account but cannot find anyway to notify HMRC about this error apart from the usual phone number. Surely there must be a way to do this online?

Hi Stephen Shepherd,
If you click on 'Ask HMRC online' and ask to speak to an adviser you will be put into the queue for Webchat and we can review this to request a cancellation of the cheque. Self Assessment: general enquiries
Thank you.