When I'm trying to contact technical support that asked me about phone number and also when I'm put my phone number just tell me it's not correct What can I put and this say to me website not accept this phone number so how can I contact number

please please can you help me because I am make a lot of reports and no anyone reply to me as so I have problem in my fingerprint in mobile when I am download the last version of a 50 mobile the fingerprint not working how can I fix it it without for...