When they got mine wrong I used the online complaints system and attached a scanned copy of the V5 showing that I had completed Section 1 to change the Revenue weight but also amended the Vehicle details section to change the Max permissible mass. I got a quick response with an apology and a correct V5 arrived within a couple of days. Because it was clearly their mistake they didn’t ask me to return the incorrect V5. It would help if they put an extra box in Section 1 to cover Max permissible mass as well as Revenue weight but they don’t so you have to find and follow their less obvious instructions for changes not covered by Section1.
