Mold in the kettle

Mold grew inside of a kettle.
Though it is over only for two months since I buy it.
Besides, the price was slightly high.

There was another kettle which my mother bought before buying.
The sound that it informed that hot water was boiled was too loud.

I bought a new one and have made a main kettle forcibly.
If mold grew in it, I am not good.

Though I washed a kettle, the mold does not readily fall.
It did not be clean even if I rubbed it with a melamine sponge.
I washed it with a scrubbing brush.

It was hard I put a hand in a kettle, and to wash it.
I have been late for going to the barbershop.

Will mold continue growing into this kettle all the time?
I continue washing it and will be late for a date next time?
Of course I do not have the partner.