Caravan

Have any caravanners had problems with fully wired 13 pin electrics on the X3? Our new X3 came with a factory fitted towbar but the electrics incomplete e.g caravan fridge not working, caravan 12 volt electrics not disconnected during towing, leisure battery not charging during towing. Dealer tells us they cannot remedy because of potential fire risk and if we use an independent specialist to wire up, we lose the warranty. Surely this cannot be true? Any comments please?