Unexpected contract changes

Endless problems with the company: My original contract had fibre internet and free voice service. They were working OK for a few years, but in September-October 2022 the phone service stopped working. It was reported to Supersonic multiple times and, finally, after 6 or 7 months the service was restored. Supersonic had to transfer VOIP service to a different provider, but it was confirmed it won't make any changes to my current contract and my payments. It wasn't true: the current bills include phone service as separate items, significantly increasing total cost. All reports to Supersonic are ignored, not answered - no actions done.