Residence permit renewal /Student/SGB

I'm in the process of renewing my residence permit as an international student, along with my partner on a family reunion permit

I have about a year left in my studies and work part-time. My partner also works part-time in a skilled position. After a number of misunderstandings with the immigration office and multiple emails and calls, they finally informed us that they believe our combined income is not sufficient. They said that we need to show proof of 1550 EUR per month.

Based on our last six months' payslips, my net income is 1039 , and my partner's is 1057. You can see the picture for for formula they are using.

Although our salaries increasing by 30-40% starting this month, they will not consider this.

According to the SGB formula they use, our salaries are calculated as 700 EUR each, totaling 1400 EUR, leaving us short by about 150 EUR.

I want to understand if this SGB formula is relevant to our situation and whether it is used for residence permit applications. I’ve never heard of this from friends who have applied, even with lower incomes.

They offered the option to open a blocked account for 150 EUR per month for two years, which I’d prefer not to do.

Thanks in advance for any advice or experiences you can share.