I've been following Balkan Telecom for several years and they appear to have been reselling services on both Tooway and Avanti-Hylas/iDirect. Their web site
https://balkantelekom.net/en/home-2/ claims 2254 customers in total.
If they have ceased service for their Tooway customers I would have thought that any other reseller, for example, Bentley Walker, could have taken over those customers, with the continued provision of service.
More information please from anyone hearing from Balkan Telecom. Is the problem specific to the country of Turkey ? Does it affect both Tooway and Avanti/Hylas customers ?
Best regards, Eric.