"[I'm] watching old Hills [episodes]," Montag, 23, Tweeted Wednesday. "I miss you @AudrinaPatridge and most of all @laurenconrad."
Montag, who recently Tweeted she "has no friends," reportedly changed her phone number and has had no contact with any of her Hills cast mates (besides Pratt, with whom she shares custody of their dogs) since she finished filming the show.
Montag did not appear in the final episode of The Hills.
A rep for Conrad did not return a request for comment, and because Patridge is out of the country, her rep says she cannot be reached.
Source: People