Connecting financing BMW Bank

Good day. I have a car financing or balloon financing at the BMW Bank. I bought the vehicle in 12/2018. My monthly rate is €257. I have already withdrawn the insurance. The closing rate is due in January 2022 in the amount of 16 thousand euros. The following problem: I wanted to lift a loan from my house bank for the vehicle to replace the vehicle there. It was rejected, on the grounds that the Schufa Score (M) was the reason. I rowed. When I bought the car from BMW, the problem was that the BMW Bank reported the financing to Schufa without specifying a term and without correcting the remaining amount. Meaning, the loan taken by BMW Bank is there as if I didn’t pay. I then called the BMW Bank and asked why it would be that way. It would probably be common for a ball to go to Schufa and ask why it would happen. So I went to the local banks, which refused to refinance me. Reason for this; temporary work company would currently be an exclusion criterion. Now to the temporary work problem: I was unemployed because of which my former business went bankrupt, all were dismissed. Thus I received last year from June to the end of August ALG1, and wanted to get back to work as soon as possible. So I applied to the temporary employment company to have a job, which also worked successfully. Now I have been working in the current company since last September, where, according to the talk, the takeover is to take place soon. Nevertheless, I would like to have a plan B. What if the company keeps me there and no takeover takes place until next year, how does it work with regard to the follow-up finance? could they also refuse me the financing of the closing rates or the financing of the connection like the banks on the spot, because of the temporary employment company? I ask for advice, please do not ask with advice like: mother or father or parents, they are unfortunately no longer there. Thank you very much.