The One Next to You 2009 one on netflix

A young, beautiful, well-off but lonely woman starts receiving mysterious SMS messages on her phone. No, she is not threatened in any way, on the contrary – an unknown man confesses his love. A short and independent investigation shows her that none of the habitual and familiar cavaliers is simply not capable of such a thing. To talk to a stranger is not possible – “the called subscriber is switched off or is not in the network coverage area”. After another “letter” she is not quite legally trying to find out who owns the phone with a number that never answers. The result is disappointing – the handset is registered in her name. Then she decides to send a reply SMS message and gets a reply….