Unable to withdraw from Grand Signal Markets Limited

I was introduced to MetaTrader 5 by my online friend and opened an account at Wintersnow Limited and made a 10000USD deposit. Wintersnow Limited informed me that Broker changed from Wintersnow-Server to GrandSignalMarkets-Server; I logged in with the new account and the account funds remain unchanged; I deposited up to 42000USD.
I requested the withdrawal from my account on 24th August 2022, the Platform Customer Service requested a 5% of service fee; and Platform Customer Service told me that I was unable to withdraw my fund without paying the 5% service fee.
My friend and I paid the service fees on 26th August 2022 and the Platform Customer Service told me that I would receive the withdrawal after 2 working days. I realized that I am unable to log in to my account since 29th August 2022. The fraud platform Grand Signal Markets Limited allows trade and does not allow fund withdrawal. The account cannot be logged in and the Platform Customer Service disappeared. I sent a few emails to them and no reply from them.