Firstly thanks to Plusnet staff for work at a difficult time. I am not expecting an immediate answer!
I am using my home phone a lot more than usual and was advised to top up. I did this for £20 on 26 March using credit card, but it never took effect. Now I have my credit card statement, and the £20 to Plusnet is there. Please can it be credited to my account.
(I subsequently topped up by £35 and £20 using my debit card, and this worked fine.)