How to get to Melksham from Trowbridge?

I need to get TO Melksham FROM Trowbridge (in the UK)

I'm thoroughly confused by the bus time tables I've found online

Can somebody explain to me where I can catch a bus - as in, where the bus stop is exactly and when the bus leaves?

I need to get there pretty early in the morning (I need to be there by twenty past nine at the latest)

There are also no trains, as far as I can see.

The only other option is a taxi - but aren't they super expensive?

Anyways, any help is greatly appreciated.

It's on a weekday, not at the weekend by the way.

Thanks