Halfords Tunbridge Wells review: Tunbridge wells bycycles

I bought a Valour carrerra last night - advertised price 335£ - it was from the shop floor and - when I got to the till - I was told it had slime im the wheels - so I need to be charged an additional amount - which I didnt query - as I thought this was standard - my partner said that I should only have had to pay - the price that ot was labelled at. The label didnt say - it was that price in a box
I came down to see the manager of the department in tunbridge wells and was told id agreed to it. - I said i had - but didnt realise that I shoukd only have paid the price that it was advertised at and there was nothing on the label to suggest any extra price.

Online it says slime is an optional extra - and nothing was noted in the labelling - the manager at Tunbridge wells - just kept repeating it agreed to it - and didnt see my point of view - i said it was disingenuous labellelling on the ticket.
He kept saying that was boxed price - when I've read up about it and tsken advice - I understand that i should have been given the option to have had the slime removed - as the tyres are protected or have additional protection from the factory - the manager was repetitive in saying that was the boxed price and didnt seem to understand that I coukd have been offered that - he saud i could bring the bike back for a refund but that he woukd not refund the additional £1÷ - i said so you could rather take the bike back . I said can your company afford to do that? - rather than uphold retail rights - as my understanding is that - even after an item is purchased - i still have rights. As I shoukd only have had to pay the advertised price - he saud that was not correct and I dint have any right as I paid the money .

Please advise . As I thought retail rights are important in this country?
It was not explained that the price was a box price 'the label with th e price - didnt indicate that there were additional costs - nor was i given the option of having the slime removed if I didnt want to pay the extra.? I akso looked online- it didnt give one price for in a box OR from the display but the prices were the same.

The manager laughed when I saud Trading Sysndards will be contacted '
Please advise