I am a caravanner and have been told that I cannot use it when I am towing

I have got onto RAC to see if there is a possibility of negotiating a cover that would "splice" into the Motabilty package and give me, for an additional fee, a full policy covering me for thre lot.
RAC came back that they were unable to sort out anything - but I could buy a Full recovery policy which would cover the caravan.
Since then I have taken out a "Recovery Only" service form the Caravan Club but this is not the ideal situation.
Has anyone else any ideas on the fiasco?
Furry Fred