The police would not have taken the ticket, the stewards would have. Police are only there. to assist stewards who enforce all the ground rules I.e. Ejections are by stewards, telling people to sit down is by stewards and jobsworth 'you've been drinking out of a hip flask' is the job Of stewards. Police are only there if it gets out of order and people chant stuff about boyfriends....!
If, by somewhat remote chance the Police did actually take it then you should have been given a receipt. Oh, and they would not have breathalysed you unless you were driving your car around the Northam end.....
Best chance I reckon is as someone already has said, approach the club tomorrow calmly and objectively asking for an explanation I you could phone the echo and get a grumpy picture of you on the front although I suppose you won't have your ticket to show....!
Good luck against the jobsworth