What does suspension of trading in a stock mean?
When the stock stops trading on the exchange due to non-compliance with regulations, its called suspension (i.e the stock is no longer traded on the market).
If a company is suspended does not mean their shares are worthless or their value is zero, It just means they are not allowed to trade on an exchange.
Suspension of a company from trading, by the exchange, might be for several reasons but if the suspended company complies with all regulations, the suspension will be revoked and the shares will start trading again.
But If the company gets suspended and then eventually closes you will have to write it off as a loss, there is nothing much you can do about it.