Bad after sales service.

I bought a Hisense 65U8A TV on 11 March 2019. On 24 May 2019 I noticed a dead vertical line. On 27 May 2019 I logged a service call with Hisense and they indicated to me that a technician will come to my house within 3 working days. After numerous calls (8 in total) I have still not received any feedback, nor have they collected my TV.