Defect elimination - Should the house construction company be requested to pay?

Hello,
we wrote a defect complaint regarding electrical work to our general contractor last year. They assured us by email and telephone that we could hire an electrician ourselves, as the electrician who was originally assigned had become insolvent. We had the work carried out and also received written confirmation that the home construction company would pay the invoice. Since there was no reference number of the home construction company on the craftsman invoice, we agreed that I (the builder) would advance payment and then be reimbursed on my account.
Unfortunately, nothing has happened in this regard for 2 months. After several inquiries (very difficult to reach), I was informed that the invoice is with their accounting department and I can expect the transfer (the amount is about 500 EUR).
In the meantime, I have learned that the company is not in a good financial position anymore. I now want to claim the money; what options do I have?

2.
Cracks are now also visible on the plaster (area of insulation of the exterior floor ceiling). I had also addressed this and the warranty manager wanted to take a personal look but again: no further actions on their part.
Through other "affected" parties, one learns that payments are being withheld there and instructions exist to delay everything, etc.
In any case, I will write another defect complaint tomorrow, because otherwise, in the long run, I will be the one who gets the short end of the stick.

Should I already go to a lawyer for these two items or do you think it would still be possible with dunning letters (what would that look like?) and defect complaint plaster facade? Before I go to a lawyer?

I also mentioned this and the warranty manager wanted to take a personal look, but here too: no further actions on their part. Through other "affected parties" one learns that payments are being withheld there and instructions exist to delay everything etc. Here, however, I will definitely write a complaint about defects tomorrow,

Whatever a "warranty manager" is supposed to be, write your complaint about defects. Overall, the description sounds to me as if the general contractor is cheerfully in the middle of fraudulently delaying insolvency (punishable, contact: public prosecutor's office) – obtain reliable witness statements from the "affected parties" or share these with the public prosecutor's office.

We had the work carried out and also written confirmation that the home building company will pay the invoice.

Whether you see in this only an insolvency claim or also fraud, legal advice might be advisable. Also regarding the question of how big a fuss you should make or not. That depends on what warranty claims you still expect from the general contractor. If the 500 euros are your entire "disputed amount," the expected return hardly justifies the attorney’s fees.

Because of 500 EUR? Book as tuition fees, never advance payment, and that's it.

The company has now filed for insolvency.

We also have the problem of a roller shutter that no longer goes up/down (crack on one slat). However, we are supposedly at fault because roller shutters must not be moved during frost...
The general contractor did inform the window installer, but they rule out a defect and request a maintenance log for the windows/roller shutters (none of the people I know do such a thing). I received a repair quote from the window installer but find it overpriced (400 EUR just for travel costs alone). Since all the other roller shutters automatically stopped due to frost but this one did not, I suspect it is more of a material defect or that the drive should have stopped (roller shutters were frozen at the bottom).
The warranty period is supposedly over (start 09.2021; damage was 01.2024). How could I report the roller shutter as a defect here? Should I commission a specialist company to evaluate it?

When did the damage to the [Rollo] occur? There is no frost at the moment.