What is going on?

Still having problems with my tumble dryer cutting out before it cools down and switching itself off.
Yes all areas of machine are kept lint free and water free and yes looked in manual and nothing in there to help. Even called someone out and said if it still works then he cannot do anything unless it completely breaks down. Now it is very temperamental as cools sometimes but beeps and switches off. Yes I know it is a fault due to flashing lights and beeping but I had to pay the person to come out and he didn't do anything as he said that it still starts and the flashing and beeping happens whenever the machine feels like it. Electra Tumble dryer TDC7100S. It is only 2 years old and was told unless it stops working completely then call someone out. Absolutely ridiculous