diff --git a/app/src/main/java/com/utsmm/kbz/ui/qr_pay/RefundCertificateManager.java b/app/src/main/java/com/utsmm/kbz/ui/qr_pay/RefundCertificateManager.java
index c52245d..4bff838 100644
--- a/app/src/main/java/com/utsmm/kbz/ui/qr_pay/RefundCertificateManager.java
+++ b/app/src/main/java/com/utsmm/kbz/ui/qr_pay/RefundCertificateManager.java
@@ -65,7 +65,7 @@ public class RefundCertificateManager {
             // ---------- CA CERT ----------
             DownloadUtil.downloadCertificateRx(
                     downloadBase + certUrl,
-                    "refund_ca_" + timestamp,   // IMPORTANT: unique filename
+                    "refund_ca_" + "file",   // IMPORTANT: unique filename
                     timestamp,
                     signature,
                     path -> {
@@ -82,7 +82,7 @@ public class RefundCertificateManager {
             // ---------- CLIENT CERT ----------
             DownloadUtil.downloadCertificateRx(
                     downloadBase + clientCertUrl,
-                    "refund_client_" + timestamp, // IMPORTANT: unique filename
+                    "refund_client_" + "file", // IMPORTANT: unique filename
                     timestamp,
                     signature,
                     path -> {