Problem ItemDetails

$before = $existingInventory->Quantity100;
$existingInventory->Quantity100 = $existingInventory->Quantity100 + ($request->BundleQuantity * ($request->Quantity100));
$existingInventory->Quantity90 = $existingInventory->Quantity90 + ($request->BundleQuantity * ($request->Quantity90));
$existingInventory->Quantity60 = $existingInventory->Quantity60 + ($request->BundleQuantity * ($request->Quantity60));
$existingInventory->Quantity30 = $existingInventory->Quantity30 + ($request->BundleQuantity * ($request->Quantity30));
$existingInventory->save();
$after = $existingInventory->Quantity100;

Problem = before ama after sama aja, ga ada perubahan

Any ideas kalaskinasah@gmail.com kalaskinasah@gmail.com ??