Paying in advance seems odd. Not having clear expectations up front compounds problems, as does unfulfilled promises of completion.

That said, it's a fair bit of work, and it's expensive. If it wasn't expensive, that's another problem. To do this correctly, he'll have to remove the neck and bridge, and reset them after the top is refinished. That's made more complicated by the original finish over heel/body joint, which is how I assume it is on your Guild.

Have you tried calling, or setting up a time to phone? Sometimes a conversation (calm, polite, kind, etc.) is the best way to resolve misunderstandings.