diff --git a/app/Services/ShorakaNewGadaiService.php b/app/Services/ShorakaNewGadaiService.php
index b7602d4..7c7d4bf 100644
--- a/app/Services/ShorakaNewGadaiService.php
+++ b/app/Services/ShorakaNewGadaiService.php
@@ -65,14 +65,35 @@ class ShorakaNewGadaiService
             $date = Carbon::now()->toDateString();
             $counter = 'shoraka:serial:' . $branch . ':' . $date;
             $latest = Gadai::on($cawangan->mysql)->where('t_gadai', $date)->max('sirig');
-            $serial = max((int) $latest, (int) $this->cache()->get($counter, 0));
-            do {
-                ++$serial;
-                $reference = strtoupper($branch) . Carbon::now()->format('ymd') . '-' . sprintf('%04d', $serial);
-            } while (ShorakaTransaction::where('norujukan', $reference)->exists()
-                || Gadai::on($cawangan->mysql)->where('norujukan', $reference)->exists()
-                || $this->pending($branch, $reference));
-            if (!$this->cache()->forever($counter, $serial)) {
+            $highest = max((int) $latest, (int) $this->cache()->get($counter, 0));
+            $releasedKey = 'shoraka:released:' . $branch . ':' . $date;
+            $released = $this->cache()->get($releasedKey, []);
+            sort($released, SORT_NUMERIC);
+            $serial = null;
+            while ($released) {
+                $candidate = (int) array_shift($released);
+                $candidateReference = strtoupper($branch) . Carbon::parse($date)->format('ymd') . '-' . sprintf('%04d', $candidate);
+                if (!ShorakaTransaction::where('norujukan', $candidateReference)->exists()
+                    && !Gadai::on($cawangan->mysql)->where('norujukan', $candidateReference)->exists()
+                    && !$this->pending($branch, $candidateReference)) {
+                    $serial = $candidate;
+                    $reference = $candidateReference;
+                    break;
+                }
+            }
+            if (!$this->cache()->forever($releasedKey, $released)) {
+                abort(503, 'Nombor rujukan dibatalkan tidak dapat dikemas kini.');
+            }
+            if ($serial === null) {
+                $serial = $highest;
+                do {
+                    ++$serial;
+                    $reference = strtoupper($branch) . Carbon::parse($date)->format('ymd') . '-' . sprintf('%04d', $serial);
+                } while (ShorakaTransaction::where('norujukan', $reference)->exists()
+                    || Gadai::on($cawangan->mysql)->where('norujukan', $reference)->exists()
+                    || $this->pending($branch, $reference));
+            }
+            if (!$this->cache()->forever($counter, max($highest, $serial))) {
                 abort(503, 'Nombor rujukan tidak dapat ditempah.');
             }
             $data = array_merge($customer, [
@@ -90,9 +111,24 @@ class ShorakaNewGadaiService
 
     public function abandon(string $branch, string $reference): void
     {
-        $this->locked($branch . ':' . $reference, function () use ($branch, $reference) {
-            $this->mutable($branch, $reference);
-            $this->cache()->forget($this->key($branch, $reference));
+        // Use the reservation lock as well so release and allocation cannot race.
+        $this->locked('reserve:' . $branch, function () use ($branch, $reference) {
+            $this->locked($branch . ':' . $reference, function () use ($branch, $reference) {
+                $pending = $this->mutable($branch, $reference);
+                $cawangan = Cawangan::on('mysql7')->where('kodcaw', $branch)->firstOrFail();
+                if (Gadai::on($cawangan->mysql)->where('norujukan', $reference)->exists()) {
+                    abort(409, 'Gadaian telah disimpan dan nombor rujukan tidak boleh digunakan semula.');
+                }
+                $releasedKey = 'shoraka:released:' . $branch . ':' . $pending['gadai']['t_gadai'];
+                $released = $this->cache()->get($releasedKey, []);
+                $released[] = (int) $pending['gadai']['sirig'];
+                if (!$this->cache()->forever($releasedKey, array_values(array_unique($released)))) {
+                    abort(503, 'Nombor rujukan tidak dapat dilepaskan.');
+                }
+                if (!$this->cache()->forget($this->key($branch, $reference))) {
+                    abort(503, 'Maklumat sementara tidak dapat dibatalkan.');
+                }
+            });
         });
     }