Try changing the address on your UK driver’s license online. If the system doesn’t recognise you (indisputable DVLA error not user input error) there is no further online option. No email address. No contact name or number. Even the email form doesn’t provide for a personal message, so they have no idea why you need their help and worse still it elicits an automated email response that simply says what is on the website that failed you in the first place. Disgraceful. DVLA fail.