Hello need a agent to renew non imagrant o visa and also tax issues please any help thanks Robert

Hi, I have a tax related problem.I'm an Austrian pensioner (61 years) living in Mueang Kanchanaburi on annual extensions of a retirement visa (no problem here). Now my Austrian pension insurance and the tax office want to have stamp and signature from a Thai tax office (Certificate of residence from the tax administration); see above. Kanchanaburi tax office says they do not do stamps or certifications, Nakhon Phatom office doesn't know what to do and Immigration says that's nonsense. Could anybody help me? Maybe some EU citizen had the same problem?