Ring Ring

After a group of telemarketers get fired by their penny-pinching boss, they take revenge by stealing the company's list of clients to start up their own firm. In the heat of celebration and a few drinks in, they lose the phone which holds the only copy of their future customers. While tracking the lost device on Halloween night, co-workers Amber and Will find themselves trapped in a demented drug addict's house of horrors. - IMDb