The real answer is you need to go to another country for 10 to 30 days to prove your not trying to live in Thailand; Everything becomes easy after that
I have a second cellphone I use as a wifi hotspot for my us phone. My tello and mint do wifi calling back to the USA for 0 extra. If I want to call local use line or for real call I need to add talk time to plan, as I only have $10 a month data on the AIS sim
You can come and go by air as you please as long as you don't appear to be living long term in thailand. So you can do visa exception, leave when you need to, stay 10 to 30 days in another country and Thailand will welcome you back. (Try to spend less than six months in the year in Thailand.