Siti Broadband — internet speed issue

Address: 20/1 Branch Panchanantala Road, Kulin Para (East), Khardah, Kol- 116, North 24 Pgs

I am using siti broadband but their service is working very slow from last 10 days at my location, pin 700116. My cwsw username : ghosh1_om. I'm using connect60 pack but my recent internet speed is below 1 mbps.
Even i called many times to their customer are and nodel officer no one pick ups the calls.
Due to the covid 19 i am working from home and depend on this broadband.
Their website also not providing any complain id where i can track.
Please look into it. They will also not extend those days.