Who called from 4088199171

They call every morning around 7:51 and when I answer there is no one there!

Called 8:15am talking about refund when asked where is refund they went silent (middle eastern accent). Caller ID came up as  GTEL

Getting same call around 8:00 last two days. Caller ID is GTEL. When call goes to answering machine, middle eastern accent says hello, hello and then hangs up. Since WE PAY for our phone services.  IT'STIME TO STOP THESE CALLS.......

They Called at 6:50 AM. How do I stop them???

Called early in the morning at 7:30 when I still in bed. Caller ID showed 'Campbell CA'. Did not answer. No message left. Could be a scam.