var a = new ManagedAccount(mOwner, mOwnerPwd);
var w = new Web3(a, mNodeUrl);
w.TransactionManager.DefaultGas = mGasLimit;
w.TransactionManager.DefaultGasPrice = mGasPrice;
Contract c = w.Eth.GetContract(mVAbi, mVAdd);

var r = c.GetFunction("issueCoin").
    SendTransactionAsync(mOwner, To, Value).Result;

Thread.Sleep(10000);

var rcpt = w.TransactionManager.TransactionReceiptService.PollForReceiptAsync(r).Result;