How can I successfully extend my Non-O visa in Thailand?

Went to jomtien immigration today to extend my O visa. First stop bkk bank pratumnak and picked up 13 month statement, and bank letter and updated passbook.. They also provided 12 credit advice letters for my incoming transfers of 65k per month. 30 minutes later off to immigration. Arrived immigration around 1030. Quick transition to the #8 desk. Everything in order and he went primarily through the 12 credit advice letters highlighting dates and transfer amounts. I was a bit worried about 2 wise transfers that went first to kasikorn, although i had already picked up two international transfer confirmations from kasikorn just in case. They evidently were unnecessary because he only verified the credit advice letters, didnt scrutinize the statement, passbook or codes. Everything else was in order though i needed to sign a few things i had overlooked. Yes they want you to sign everything. Rental contracts, pension letters, all photocopies etc. visa approved in less than 15 minutes. Pick up on monday after 2pm.