5G dialup speeds

This entire year I have been having serious issues with my 5G connection. I am supposed to get "Up to 50Mbps", yet I average between 1 and 5 (on a good day) Mbps. Logging tickets on their app is pointless as no one ever gets back to you. Only through mybroadband forums was I able to get some responses. After they replaced my router a few months ago, the terrible speeds persist. I would advise against anyone making use of them as an ISP as it is not value for money. I will probably have to move to another provider as Rain is not interested in resolving the issue