I had the same problem but eventually got sorted
Speeding Fines issued when stopped by a Police Officer How can I pay my Fixed Penalty?
Merseyside Police are unable to accept fixed penalty payments. However payments can be made using Credit/Debit card by contacting the Court Fixed Penalty Payment Line on 0845 600 0490 and quoting your Fixed Penalty number.
If your notice was issued within the Merseyside area, send your exact payment to the HMCS, P.O Box 817, Liverpool, L69 2AF.
Cash should be sent only by Registered Post. Cheques, Postal Orders and Money Orders should be made payable to the HMCS and crossed. Please include your name & fixed penalty number on the reverse of the cheque. Post-dated cheques will not be accepted.
ALWAYS REMEMBER BIG BROTHER IS WATCHING YOU:::::::: Have a nice day and an even better one tomorrow