diff --git a/src/main.ts b/src/main.ts
index 3f8b126..0e7a2d3 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -31,46 +31,58 @@ const checkAddress = (address): string | false => {
     console.log('KingOfCoins is online!');
   });
 
-  // Create an event listener for messages
+  // Event listener for messages
   client.on('message', async (message) => {
-    if (message.content.startsWith('!ser')) {
-      if (message.channel.id == config.discord.channel_id) {
-        console.log(`Received "${message.content.slice(5)}" from ${message.author.username}`);
-
-        const address = message.content.split(' ')[1];
-        const checkedAddress = checkAddress(address);
-        if (!checkedAddress) {
-          message.channel.send(`I don't understand this address, ${message.author.username}... 😕`);
-          return;
-        }
-
-        const promocode = message.content.split(' ')[2];
-        if (!activeCodes.includes(promocode)) {
-          message.channel.send(`Invalid promocode, ${message.author.username}... 😕`);
-          return;
-        }
-
-        const entry = await db.getCode(promocode);
-        if (!entry) {
-          if (isProcessing) return;
-          else isProcessing = true;
-
-          const success = await sender.sendTokens(checkedAddress, amount.toString());
-          if (success) {
-            await db.saveOrUpdateCode(promocode, address);
-            message.channel.send(
-              `Sent ${amount / 10 ** 10} ZBS to ${message.author.username} against ${promocode}! 🎉`
-            );
-          } else {
-            message.channel.send(`Sorry, something went wrong! Please try again...`);
-          }
-          isProcessing = false;
-        } else {
-          message.channel.send(`Promocode already used! 💼`);
-        }
-        return;
-      }
+    // Validate channel
+    if (message.channel.id !== config.discord.channel_id) return;
+
+    // Validate message pattern
+    if (!message.content.startsWith('!ser')) {
+      message.delete();
+      return;
+    }
+    console.log(`Received "${message.content.slice(5)}" from ${message.author.username}`);
+
+    // Validate address
+    const address = message.content.split(' ')[1];
+    const checkedAddress = checkAddress(address);
+    if (!checkedAddress) {
+      message.channel.send(`I don't understand this address, ${message.author.username}... 😕`);
+      return;
+    }
+
+    // Verify promocode
+    const promocode = message.content.split(' ')[2];
+    if (!activeCodes.includes(promocode)) {
+      message.channel.send(`Invalid promocode, ${message.author.username}... 😕`);
+      return;
+    }
+
+    // Validate promocode
+    const entry = await db.getCode(promocode);
+    if (entry) {
+      message.channel.send(`Promocode already used! 💼`);
+      return;
+    }
+
+    // Address is eligible to receive tokens
+    // Check if no pending txns are present on polkadot-api
+    if (isProcessing) return;
+
+    isProcessing = true; // Lock polkadot-api
+    const success = await sender.sendTokens(checkedAddress, amount.toString());
+    isProcessing = false; // Release polkadot-api
+
+    // Validate response from polkadot-api
+    if (!success) {
+      message.channel.send(`Sorry, something went wrong! Please try again...`);
+      return;
     }
+
+    // Add code redemption entry in db
+    await db.saveOrUpdateCode(promocode, address);
+    message.channel.send(`Sent ${amount / 10 ** 10} ZBS to ${message.author.username} against ${promocode}! 🎉`);
+    return;
   });
 
   client.login(config.discord.token);