Similar happened to me last August (MG5 Trophy) on motorway with family on board. The car was serviced by Virtu MG Edinburgh West who recovered the car and drove us home without charge (good!), but it took 8 months to get fixed (2 failed battery cells). Virtu didn't have a technician to MG's required grade to assess the issue - a technician had to take a course, then scope of repair was not agreed between MG and Virtu, then Virtu did not have the tools and needed to hire from MG who had rented them out elsewhere - all in all, took 8 months. Hire car was eventually approved but was never provided and compensation was refused by MG. I went to court. MG have agreed to pay my claim in full.