Brittany Ferries complaint: No Towels

My partner and I booked our ferries through Brittany Ferries with overnight cabins for both trips. We had to pay for larger cabins as the two berth cabins were fully booked so paid the extra. The trip from Caen to Portsmouth was fine. The trip from Portsmouth to Caen was ok until we got to our cabins where there were no towels. We left our own towels in the car and could not get these as it was too late. We were concerned that the cleaning staff will think that we took the towels so I did leave a not saying that there were no towels. My complaint is that we had to pay for a four berth cabin for the two of us and pay extra and there were no towels so imagine if there were four of us. We had to use toilet paper to wipe with. We could not have a shower. Not very nice. This was not a good situation to be in and could do nothing about it.