Unstable internet connection on Fritz!Box - constant drops

Hello, I am writing here because I don't speak fluent German to explain my issue over the phone. We switched to O2 home internet about 4 months ago, and we have been experiencing constant connection drops. We are using a Fritz!Box router. For the past month, the situation has become completely unbearable — the internet disappears entirely multiple times a day on a permanent basis (in the morning, afternoon, and evening). I visited the O2 shop where we signed the contract, but the employee just gave me a phone number to call, which I cannot use due to the language barrier. This is a severe breach of service stability. Could an O2 moderator please check our line, look into our Fritz!Box connection logs, open an official support ticket (Störungsticket), and help resolve this issue? Thank you in advance