Rain 5G

Been with rain since early 2020 when covid hit due to working from home I switched to rain I was using the 4g standard sim but last year around September switched to the 5G all was well getting great speed and could do my daily work functions that was required but since January this year I’ve been complying to the service provider about how slow my 5G now is not even getting 15mps up and 7mps down on my speed test which is causing me to have to drive to the office to go work? Can this please be sorted.