The number was removed because it was probably just a random (fake) 0203 virtual number which doesn't exist. The fake caller IDs are swapped regularly so, even if someone saw it on here and noted it, it would probably never be used again for long by the scammers.
More recently, the scammers have been copying and misusing real numbers from real businesses and residential customers to use as their fake caller IDs.
This has resulted in irate call-backs from scam call recipients to the real/innocent owners of the cloned numbers complaining about receiving a scam call. This can be very annoying and distressing to the real owners of the numbers who often have no idea why they are getting such calls.
As a result, phone numbers are removed by the moderators to avoid the possibility of publishing real numbers belonging to innocent people or businesses.