About one month ago when doing my 90 days reporting at Chaeng Wattana govt office I asked for a certificate of residence, for applying for a driving license. The officer who received my application said it shouldn't take more than 3 weeks. It has now been almost one month and still nothing.

How long does it usually take to get this certificate ? Does someone come to check that you actually live there ?

in Phuket

depends on how long the line is......

Patong 5 minutes max if no people

free

Perhaps it is in the mail. I think they normally send them by EMS.

Perhaps try to give them a call to see if they have sent it yet,