diff --git a/django_sofortueberweisung/admin.py b/django_sofortueberweisung/admin.py
index 17bc159..d101769 100644
--- a/django_sofortueberweisung/admin.py
+++ b/django_sofortueberweisung/admin.py
@@ -8,5 +8,6 @@ class SofortTransactionAdmin(admin.ModelAdmin):
     list_filter = ('status', 'status_reason')
     ordering = ('-created_at',)
     fields = ('transaction_id', 'created_at', 'last_modified', 'status', 'status_reason')
+    readonly_fields = ['created_at', 'last_modified']
 
 admin.site.register(SofortTransaction, SofortTransactionAdmin)
diff --git a/tests/tests.py b/tests/tests.py
index 839dc6a..1d3df62 100644
--- a/tests/tests.py
+++ b/tests/tests.py
@@ -3,19 +3,18 @@
 
 from __future__ import unicode_literals
 
-import os, sys
 import re
-import xmltodict
-from requests import Response
-from testfixtures import replace
+import sys
 
+import xmltodict
 from django.conf.urls import include, url
 from django.test import Client, TestCase
+from requests import Response
+from testfixtures import replace
 
 from django_sofortueberweisung import settings as django_sofortueberweisung_settings
 from django_sofortueberweisung.models import SofortTransaction
-from django_sofortueberweisung.wrappers import SofortWrapper, DjangoSofortError
-
+from django_sofortueberweisung.wrappers import SofortWrapper
 from .test_response_mockups import TEST_RESPONSES
 
 try:
@@ -153,34 +152,8 @@ def test_known_transaction_refund_error(self):
         self.assertGreaterEqual(refund.errors.count(), 1)
         self.assertTrue(refund.errors.filter(error_code='5003'))
 
-
     def _create_test_transaction(self, transaction_id):
         return SofortTransaction.objects.create(
             transaction_id=transaction_id,
             payment_url='https://www.sofort.com/payment/go/'+transaction_id
         )
-
-
-class TestSofortTransactions(TestCase):
-    auth = {
-        'PROJECT_ID': '299010',
-        'USER': '135335',
-        'API_KEY': 'aeb2075b1455a8ce874749e973e61cca',
-    }
-    cafile = os.path.join(os.path.abspath(os.path.join(os.path.abspath(os.path.dirname(os.path.dirname(__file__))), 'django_sofortueberweisung')), 'cacert.pem')
-
-    def test_valid_transaction(self):
-        sofort_wrapper = SofortWrapper(auth=self.auth)
-        sofort_transaction = sofort_wrapper.init(
-            amount=1.0,
-            email_customer='tech@particulate.me',
-            phone_customer=None,
-            user_variables=None,
-            sender='Test',
-            reasons=['Just a test.'],
-            currency_code='EUR'
-        )
-        self.assertEqual(sofort_transaction.status, '')
-        # TODO: let the transaction be accepted by sofort.com
-        # TODO: let the transaction be refunded by sofort.com
-        self.assertFalse(sofort_transaction.refresh_from_sofort(sofort_wrapper=sofort_wrapper))