Can't merge a license

I've paid my license every year for 15 years but this year my wife paid it using the same reference number but now they have created a new license for her so I keep getting notifications and threats. Called "Justine" who told me to merge I need to provide proof of address, IDs, marriage certificate. Thats not happening, asked why and was told "that's what the SOP says". So looks like I'll be handed over, joys......