Might be a good idea to contact Minix Martin. If the remote is less than 1 year old, they should replace it. If you look inside the battery cover, there is a white label with a date and number on it.
Send that number and an email to Minix Martin. I have sent you his email address by PM. Don't think I am allowed to send you his address on a public forum.
In the meantime, you can still use the standard remote, which incidentally I use all the time. My A3 has sat here for the past 19 months and still functions with its original batteries.
Maybe cos I seldom use it, except to turn the box on. For some reason, the standard remote doesn't always turn the box on. Must be a senior moment remote??
Good luck.