Nameserver propagation time is somewhat of a myth.
It is all controlled by the TTL (Time to Live) values in the Domain Zone Records.
It is always best to reduce the TTL values to a matter of minutes many days before you move a website from one IP address to another.
And then, when you do change an IP address of any record, the 'propagation' will be almost instant (a couple of minutes), right across the whole Internet and you will see what everybody else sees.
In your case, it is a bit late for that ..... (although it may still help to sort things out
..... but using a tool like the DNS Report available at DNSstuff.com
will tell you what is going on. (not cheap, but it does a very good job). They give a handful of examples of what you will see for your domain.
Line One:- Zen - DrayTek Vigor 2600VG
Line Two:- EntaNet (Aquiss) - DrayTek Vigor 2600