Andiro

Hello everybody, I have a multiple entry non o-visa based on marriage, valid for 1 year. Normally I am granted 90 days stay each time I enter the country. This time I entered Thailand from Laos through a very small border in Uttaradit, where rarely a Falang is seen. First, the friendly immigration officer stamped a maximum stay of 30 days in my passport. Fortunately, I checked and made her aware of the error. I said I have a visa and should get 90 days. Then she looked at my non o year visa and stamped me the date in the passport until which the visa is valid. This is valid until July 15, 2023, which means she granted me a stay of 7 months! I told her that this was wrong and I would only get 90 days, but she did not understand this, asked her supervisor, who agreed with her. I had no time to further discuss and took it because it is not to my disadvantage I think. My question now is whether I can really refer to this stamp and have no consequences to fear, should I stay in the country for 7 months non-stop or do I have to go to immigration and make them aware of the wrong stamp and let them correct it?