Affidavit??for what pension all you need is 400,000 buats in account for 2months before you apply first extention fot first year, 3months before second extention and three months every year after ok 👌
You have to have a bank account get a visa, so my bank opened a deposit account with health insurance, the best(easiest one )is bangkok bank, did mine on beach road pattaya
If your in Thailand just use the house Internet and messenger as I do right now, sim at airport and let it run out, phone think it has a sim just use the house Internet free messenger
Just a thought, do you have a TM6 which goes online the first of may,enter and exit form, the one you used to get on the plane as you landed in Thailand???,,,at the moment it's suspended till 1st may