An IDP is only valid for 90 days for insurance and is not designed to be used long term. Repeated IDPs while living in Thailand is not recommended. Should go for the Thai licence.
Are you in a hotel or residence? They seem to be clamping down on this TM 30 thing in some places....probably mostly in Pattaya though.....catching a lot of people out recently if Landlords don't register you.
As far as I know once you get to 90 days of overstay, you have to be outside of the country for 1 year, it can't be overturned (well perhaps with another bribe), that is why they continue to pay...??