Hi Muhammad, & welcome 
The verification process has reportedly taken up to 2-3 days in the past and given that this is a bank holiday weekend, plus the extra burden on 
with the ongoing pandemic situation, it may take longer than usual.
If you’ve now hit the 48 hour mark, then you must have applied on Saturday. Saturday on a bank holiday weekend means a (normal) verification would actually start processing on Tuesday morning (tomorrow). So I’d guess that you’d be verified within the 48-hour window by Thursday morning.
I’d contact Monzo if no response by the end of business on Thursday.
More information on sign-up related issues here;