Ilmatar is an absolute disaster
This company is an absolute disaster, incapable to do proper book keeping and send notifications of invoices to its customer in due time. I've had 2 counts of invoicing issues in under 6 months. The customer service is slow, rude, and assumes that customer is lying or wrong.
To add offence to injury, instead of finding reconciliation or sending friendly reminder on an overdue invoice (though notification hasn't been dispatched in the first place), Ilmatar deals directly with debt collection companies.
Besides, in case you didn't know, wind energy isn't actually that green:
1- It is intermittent and during periods of non-production, coal & gas are used instead
2- Turbine blades are non-recyclable and end-up producing an astonishing amount of land-fill waste.
Conclusion: Do yourself a favor and AVOID, by all means, this terrible energy supplier.