No service from Hisense

We are very frustrated with Hisense and the service - or let's rather say NO service. We bought a tv in August 2021 and in October 2021 after an update it lost the apps. After 7days and numerous appointments that was made and not kept the apps returned by itself. A month later the apps disappeared again and we're in the same position as the previous time and after 5 days numerous appointments made again was not met and we're still without apps. Trying to get hold of the service manager at the call centre he is never available and empty promises of getting back to me. We lost all faith in Hisense and can never recommend it to anyone.