Keyboard Service Program — fraudulent authorised service provider

Dear Apple, dear Community,

Today I have handed in my 2016 MacBook Pro to a local authorised Apple service provider (in Kiev, Ukraine), in order to replace the keyboard in accordance with the Keyboard Service Program, given that I have been experiencing all of the relevant problems (letters repeat unexpectedly or do not appear at all and in general respond quite inconsistently). In about 40 minutes after the service provider had taken the laptop for diagnostics, they called me to say that they hadn't found any problem with the keyboard — which is simply impossible — and then immediately claimed the laptop needs internal cleaning ($25) and that they indetified a problem with the motherboard that needs repair, although aside from the keyboard the laptop works flawlessly.

Since it is commonplace in my country that even officially authorised service providers are willing to swindle customers out of money by coming up with nonexistent problems, I am afraid that the reason they had spent only half an hour testing a clearly faulty keyboard only to then call and say there is no Keyboard Service Program-relevant problem, which is most certainly not true, yet there is a few other, much more serious problems (no sign of that being true either) that they could start repairing; please suggest what is to be done in this case, given that it is absolutely impossible that the laptop's keyboard is in order and that the service provider was unable to identify problems relevant to the Keyboard Service Program.