Hisense unhappy customer!!

We bought a Hisense washing machines in August that started having problems the following month. We emailed, called, twitted and received calls with no follow up. Technician ordered a part that he never came back to install. Friday I was promised a credit for a new washing machine within 24hrs, it's been 5 days no credit email received. Been sitting with a broken washing machine for almost 3 months. Please advise on the next step 🙏