rule about using present perfect with present simple

I can't find on internet the rule.

To you native speakers, if the second part of the sentence uses present simple, does it involve using the present perfect tense in the first part because of the consequences in the present?

In the sentences: "They have for sure seen my message for the payment because I can see that my account is no longer blocked"

"The country has been colonized, this is why we can see similitaries today" but it could imply that the country is still colonized(present perfect) whereas the colonization was past.

To me, in both sentence, they do not need present perfect but I do not know.

Yes. That's correct.

Present perfect is a present tense. The topic is something that happened in the past or began in the past, but it is always indirectly talking about the present.

Your first sentence, "They have for sure seen my message for the payment..., means, "They know I have made the payment".

The second sentence means, "The country has a history of being colonized."