Superonline Fiber 100 Mbps Internet Keeps Disconnecting for a Month

I have been experiencing constant disconnections with my Superonline Fiber 100 Mbps internet subscription for about a month. I reported this issue to customer service multiple times, and each time I was told it was due to infrastructure problems. However, Superonline teams inspected the line and confirmed there were no infrastructure issues. I believe the problem is caused by the modem, yet Superonline’s technical team has not visited my address or replaced it. I request that my modem be checked, replaced if necessary, and the unfair charge on my last bill refunded. I kindly ask for a permanent solution to this issue as soon as possible.