Use an ACAccount without saving it - iphone

Question

My app has tokens from Twitter and wants to make a SLRequest with them but when I do this without saving the ACAccount it doesn't. How can I fix this?
Code:
ACAccountStore *accountStore = [[ACAccountStore alloc] init];
ACAccountCredential *credential = [[ACAccountCredential alloc] initWithOAuthToken:#"token" tokenSecret:#"secret"];
ACAccountType *twitterAcctType = [accountStore accountTypeWithAccountTypeIdentifier:ACAccountTypeIdentifierTwitter];
ACAccount *newAccount = [[ACAccount alloc] initWithAccountType:twitterAcctType];
newAccount.credential = credential;
newAccount.username = #"username";
SLRequest *request = [SLRequest requestForServiceType:SLServiceTypeTwitter requestMethod:SLRequestMethodGET URL:[NSURL URLWithString:#"https://api.twitter.com/1.1/statuses/user_timeline.json"] parameters:#{ #"screen_name" : #"username" }];
request.account = newAccount;
[request performRequestWithHandler:^(NSData *responseData, NSHTTPURLResponse *urlResponse, NSError *error) {
NSLog(#"ResponseData: %#", [[NSString alloc] initWithData:responseData encoding:NSASCIIStringEncoding]);
NSLog(#"StatusCode: %d", urlResponse.statusCode);
NSLog(#"Error: %#", error);
}];
Log:
2013-06-20 00:07:55.554 MyApp[6009:c07] ResponseData:
2013-06-20 00:07:55.555 MyApp[6009:c07] StatusCode: 0
2013-06-20 00:07:55.555 MyApp[6009:c07] Error: Error Domain=SLErrorDomain Code=0 "Could not prepare the URL request." UserInfo=0x9499020 {NSLocalizedDescription=Could not prepare the URL request.}