I do wonder if it would have been a different response if I’d bought the bike from a Specialized dealer rather than Halfords. Here’s a genuine question, what would happen if you bought a bike from a Specialized store in the south of England then moved to Glasgow and needed some warranty work done by the local dealer? Would you honestly be expected to return the bike to the original dealer? According to the warranty yes, but in reality that’s a daft expectation.
I had this when the chainstay cracked on my Trek Fuel (bought online as they were doing 0% finance). Was told by Trek I could return it to the original shop and get it sorted, parts and labour FOC or take it to local Trek dealer and get the parts free but pay for the labour. Chose LBS as it seemed less hassle and labour was only £40.