Jennifer Aniston is reportedly furious her telephone call to congratulate ex-husband Brad Pitt on the birth of his daughter was blocked by his new lover Angelina Jolie.'The Break Up' actress wanted to show she had no hard feelings towards her former spouse and tried to phone Brad to offer her congratulations on the arrival of Shiloh Nouvel.However, Angelina allegedly prevented her man from taking the call.A source told Britain's Grazia magazine: "She thought it was the right thing to do. But she couldn't get her call accepted. Jen thinks Angelina has changed Brad and made him as insensitive and uncaring as she is."The alleged call is the latest attempt Jennifer, who is now dating comic star Vince Vaughn, has made to try and make peace with her ex and his new lover.The source added: "As far as Jen is concerned, not taking her phone call was the last straw. She had intended to be civilised and be nice but Brad and Angelina don't seem to want to do that."