No there isn't one way to save a significant amount, Wise better rate but higher fees than a thai bank. For larger amounts like 1m baht most people just use swift, make sure you send Euro, not baht, better rate from thai bank
I set up the Halifax clarity card, i just put in card details, i didn't need to call anyone.
The problem may be with the card, have you used it recently? Maybe the call isn't working because you don't have enough balance on your sim
I was riding down the 332 about that time, mostly a safe road, but if you have some bad luck and encounter a drunk driver / driver using the phone, maybe game over.
Safety in numbers