No after sales support

We had such a wonderful experience with Alumo when they installed our solar but after installation support has been terribly disappointing.Current our solar charges the batteries and this energy is being used during the day but at night it uses Eskom electricity although the batteries are fully charged.My husband have logged several calls with them and have send mails only to receive no feedback and support.It is so frustrating as we are going to end up with huge Eskom bill when we could have used our solar energy.