lingo: warn user if the payment service failed to answer properly (#11064)

combo/apps/lingo/views.py

@@ -282,7 +282,9 @@ class ReturnView(View):
             # if eopayment can't get response from query string redirect to
             # homepage
             logging.error('failed to process payment response (%r)', e)
-            return HttpResponseRedirect('/')
+            messages.error(request, _('We are sorry but the payment service '
+                                      'failed to provide a correct answer.'))
+            return HttpResponseRedirect(get_basket_url())
 
         if payment_response.result == eopayment.PAID:
             messages.info(request, _('Your payment has been succesfully registered.'))