Had Yao : Banks
There is no shortage of branch banking in Phuket. There seems to be a bank or an ATM every other block on the island. Some are open on Saturdays and all provide money exchange services.
Foreigners with retirement visas or business visas can open an account at a Thai bank though policies and requirements vary from bank to bank. Recommendations by ex-pats can be very helpful on which bank one should choose.