Mine would probably do the same thing if it knew it was going to church.

That aside, it definitely is not the timing belt.

When you try and start it, does it make a low whirrrring sound, or just a click??
Whirring sound means your flywheel has become disconnected and also suits the other symptoms.
Click could mean other things have happen like a seized engine etc.

Now, it depends on what the transmission guys did, as to whether they had the flywheel off. They should not have had it off, but maybe they did.

Good luck.

PK