ARe we really safe on facebook? Is our privacy guaranteed?

Facebook vulnerabilities
I have heard that you are about to have a new development in the incorporation of both instagram,messenger and whatsapp in a sort of intergrated messaging procedure but before you do this i wanna alert you on and of some holes in your social media platforms...
One is the authentication and verification of a phone number associated with a given account on some of the social mediaccount e.g especially those created using an email account as   . . a login id ,these accounts are usually compelled to add a phone number which must be verified but on such accounts one can temporary use a phone number without verification for a couple of weeks or more month because on the three facebook accounts iam testing iam and gave been able to use one phone number to login to three different facebook profile accounts;where one is originally verified while the two others are temporarily using it,a phone number verified to be a login id of another different facebook account can be added and used as a phone number on another account meaning that one phone number can be used to log in to more than two different accounts.this is possible becaustoon some browsers and Facebook pplication on some chinese made phones,one can add such a number and he/she doesn't verify it yet it still can be used as a login id for that account,this means that there is a problem with facebook's database.however i have come to prove that this phenomenon is mainly common on browser that are inbuilt on chinese phones or on facebook applications inbuilt on chinese made phones...!!!!thus am compelling the facebook development team to revise their database and make sure that one single phone number must be used " only and only" on one facebook account.
Which official phone numbers from facebook are allowed to send password reset messages to us?
I think many may be not aware that some phone numbers which aren't official facebook's number do send reset codes yo our registered phone numbers.they end up even sending facebook links for reseting our passwords which are phish.in some countries where telecommunication companies aren't  indipendent, i think government security bodies can force them to surrender facebook users' numbers and some times can divert messages to their numbers so as to interfere with their works on facebook.i have also a belief that these governments have used the ss7 exploit to divert messages to phone numbers of facebook accounts that they think is a threat to them.i have had many scenarios where certain phone numbers from some african country owned by security agencies have been sending password reset messages and reset links whenever one tries to reset his or her account password!! Its really shocking how local number can send one a message if he or she tries to reset his or her password.this messaging from localphone numbers also does occur on Instagram.why does facebook send a message via another number not their own official number?are there local phone numbers that are suppossed to send such messages?if facebook is aware of this or not,then facebook must know that it is very dangerous to someones security and privacy more especially here in africa where governments try all means to interfere into people's privacy...what facebookand instagram must do is to make sure that phone numbers registered with profile accounts are the ones which must recieve reset messages and such messages from their web database must not pass via any diverted number.i think facebook has much changes to do and implement on its database.