TCL is one of the few companies that support 'right to repair' and have parts available for DIY repairs. Sites like iFixit may have some troubleshooting and repair instructions. I would start there or a Google search with your TV and symptom; to see of there is something you are missing maybe that specific model has a slightly different remote pairing process or a known bug with a workaround.

I know you are looking for on-site repair. I would not imagine there is anyone in BCS who would do any repair onsite. Just the service call alone would put you close to 50% of what a brand new 65 inch TCL would cost.

Very few people are doing onsite repairs for televisions. It's now pretty much limited to higher end TV's and broadcast equipment. Even then, onsite is limited to large metro areas. People who do events now carry spare TV's and broadcast monitors versus spare parts.

If it's a Roku TV you can use your phone or even an old phone as a remote with the Roku app as a workaround. I had a Roku TV in the garage and used an old phone to Bluetooth music to a receiver and used the Roku app to control the TV after the original remote died.

Good luck, hope you find a resolution.