Back in November I purchased a new iPhone 5. Since moving in with my roommate, who I just met in January, my calls have been going to her phone. If I decline a call it would start ringing on her phone. Now it doesn't happen with every phone call but a majority of them have been going to her. We have the same service provider, Verizon, but we are on two different plans. Remember I just met her so there is no way we would be on the same plan. She has the iPhone 4, which is about two years old. When this first happened I thought it was weird but it kept happening. We first checked call forwarding on both our phones and it was disabled on both. After about the 4th time it happened we decided to go down to Verizon and Apple, which were no help. Verizon called there technical support and checked the data on our two phone and according to the data our phones have never crossed paths. So we went down to Apple and they changed my SIM card but still the problem keeps happening. We do not share any apple ID or have synced our phone with one another. We went back down to the apple store today and they still say they have never heard of this happening and insists its not a hardware issue, which at this point I find that hard to believe. My roommate and I don't know where to go from here because Apple doesn't believe us and sends us to Verizon and Verizon just sends us back to Apple. Could this be a hardware/ software issue with the iPhone? Should the SIM card have fixed it? Thoughts or suggestions would be much appreciated.