Tourist visa to long term visa

I’m a tourist visa here in japan, my mother wanted me to come here because she just had an operation, then after a month my mom decided to go to the immigration for the change of status, the hagaki arrived , I applied last sept and it arrived this feb. We went to the immigration and it said it was denied then after that my mom talked to the person from the immigration and he said that I shoud return this 26 to get my birth certificate and coe, I don’t know why because I couldn’t understand what they were saying, then he gave back the hagaki plus the paper from the immigration, then he wrote something on the hagaki, then my mom told me that he said we should bring the birth certificate, coe plus 4000 yen when we get back on the 26th of february. And by the way my visa is until the 27th but he insisted that we should go back on 26th and not 25th or 27th or any other day. What does this mean?

I really dont know the content of your message.

Normally if you have been declined you need to apply again (6 months later)
In this case maybe they are asking additional documentation, but never heard that you can have approval right away after handing in the additional documentation.

Rather than asking people here, you should go to immigration office and reconfirm what had been said to you.

We don't know the actual content of what had been said/explain to you by immigration officer.

You may have misunderstood what have been said and try to post it here, which we may also misunderstood and thus may give your wrong information.

Best just go again to immigration with whatever that was returned to you (paper and hagaki) that had
been given to you, and ask for more clarification. Bring someone who can understand and translate Japanese.

the birth certificate, coe plus 4000 yen

I don't think you have COE (for long term) since you enter as Tourist and did change of status?
Normally change of status application, there is no COE involved unless you applied earlier.

Normally for change of status/visa related, you will need a revenue stamp, they will not accept cash.
Maybe the immigration ask you to prepare 4,000 yen worth, in case your application is approve, then you will need to go buy revenue stamp (Shunyuinshi (しゅうにゅういんし or 収入印紙)) at the nearest post office or convenience store.

Normally the 4000 yen is for a 14 day extension.

So the 14 day starts on the day you go into immigration and apply. And you most likely wont be granted the extension if you go after your current expiry day.

I think that is what the immigration officer was attempting to convey.

But again, with knowledge of what was said, then best to go back in and don't leave until to understand what has been said to you. Take someone in that speaks Japanese with you.