Creating a new entity, and updating another at once - datetime

Question

I've searched a lot about this, and seriously asking is my last resource, doctrine is kicking me hard.
I have an entity named "Contract" and another "Request", a Contract may have several Requests, when adding a new Request I search for an existent contract of that client and associate it if already exists or create it if not.
In RequestRepository.php:
public function findOrCreate($phone)
{
$em = $this->getEntityManager();
$contract = $this->findOneBy(array('phone' => $phone));
if($contract === null)
{
$contract = new Contract();
$contract->setPhone($phone)
->setDesDate(new \DateTime());
# save only if new
$em->persist($contract);
}
return $contract;
}
The thing is, when the contract is new it works ok, but when is "reused" from db I can't modify its attributes. I checked the OneToMany and ManyToOne already.
In Contract.php:
/**
* #var integer
*
* #ORM\Column(name="id", type="integer")
* #ORM\Id
* #ORM\GeneratedValue(strategy="AUTO")
* #ORM\OneToMany(targetEntity="Request", mappedBy="contract")
*/
private $id;
In Request.php:
/**
* #var string
*
* #ORM\JoinColumn(nullable=false)
* #ORM\ManyToOne(targetEntity="Cid\FrontBundle\Entity\Contract", inversedBy="id", cascade={"persist"})
*/
protected $contract;
I also have a method which modifies an attribute within Contract.php:
public function addTime($months)
{
$days = $months * 30;
$this->des_date->add(new \DateInterval("P".$days."D"));
return $this;
}
I create the request and "findOrCreate" a contract, but if the later is not "fresh" the addTime does not save to db.
What am I doing wrong?
Edit: The controller is a common CRUD with minor modifications.
Don't worry about "request" name clash, the actual code is in spanish, Request = Solicitud
public function createAction(Request $req)
{
$entity = new Request();
$form = $this->createForm(new RequestType(), $entity);
$form->bind($req);
if ($form->isValid()) {
$em = $this->getDoctrine()->getManager();
$entity->setUser($this->getUser());
$data = $request->request->get('cid_frontbundle_requesttype');
$phone = $data['phone_number'];
$reqRep = $em->getRepository('FrontBundle:Request');
$entity = $reqRep->newRequest($entity, $phone);
return $this->redirect($this->generateUrl('request_show', array('id' => $entity->getId())));
}
return $this->render('FrontBundle:Request:new.html.twig', array(
'entity' => $entity,
'form' => $form->createView(),
));
}
The newRequest:
public function newRequest($request, $phone)
{
$em = $this->getEntityManager();
$contractRep = $em->getRepository('FrontBundle:Contract');
$contract = $contractRep->findOrCreate($phone);
$contract->addTime(123); # this is the problem, I use var_dump and this method works, but doesn't persists
$em->persist($request);
$em->flush();
return $request;
}

Answer 1

Eureka!! The issue was that doctrine seems to check the objects by reference, and all I did with the contract was adding a DateInterval to a DateTime property, so the object was the same for doctrine's matter and there was no saving. This is the code that made it.
public function addTime($months)
{
$days = $months * 30; # I know DateInterval has months but this is company policy ;)
$other = new \DateTime($this->des_date->format('Y-m-d')); # creating a brand new DateTime did the trick
$other->add(new \DateInterval("P".$days."D"));
$this->des_date = $other;
return $this;
}
Thanks for everything #cheesemacfly.