guy called, he said hello # times then hung up?????

I received several phone calls from this number but they never talk or leave any message.

Caller:(905) 905-7888

Not a legitimate number. Anything with two overlayed or adjacent Canadian area codes in the prefix for the same number is not issued, per http://cnac.ca/co_codes/co_code_status_map.htm and http://cnac.ca/data/ac905.htmThat means that +1-613-343-xxxx, +1-416-647-xxxx,  +1-905-613-xxxx, +1-905-416-xxxx, +1-905-905-xxxx and the like do not and *cannot* exist. 905 is an area code, not a local exchange.The caller-ID info is therefore bogus.No idea, then, why this number just called my mobile 'phone in direct defiance of the do-not-call list.

get phone call four or five times a day,they never leave a message

I get a call several times a day.  I never answer but notice that the call comes immediately after someone else has been talking to me.  Not much fun with a broken leg.

This caller never answers when I lift up the receiver.Haven't a clue who they are except to say they are a nuisance.