'E' key sticking and repeating

I have an early 2015 MacBook that I purchased in Singapore in early 2016. Earlier this year I started having problems with the 'e' key sticking and repeating. It was intermittent and an air blower seemed to clear the issue for a while. It has now become unusable as it repeatedly types 'e'.

I discovered that Apple have a recall program on my keyboard type and model but when I took it to the authorised service centre they pointed out that my purchase date was over 4 years ago and so the fault wasn't covered under the warranty.

This seems harsh given that it's a know fault with the butterfly keyboards and most of the 2015 machines must be not covered either despite being one of the affected models.

Anyone have any ideas how I can resolve this?

Cheers

[Re-Titled by Moderator]