Re: Need to replace mouse on desktop set

But over the last month my mouse is
always double-clicking for every single click I make, and is driving me

This is quite common - the microswitch goes noisy.

If the manufacturer can't help, perhaps you could find a local electronics hobbyist or repair shop, and ask them to change the microswitch. A good workaround, if the microswitch is a type not easily available, is simply to swap the left and right switches. They are almost always identical.