Even if they did breach the contract, what recourse do you think the OP would deserve other than a refund?
The short answer is none as the OP has been put back into the position they were in before the contract started. There is no scenario that I can see that the OP would be reasonably due any other form of compensation in this kind of transaction and the UK doesn't have punitive damages.
It's interesting, I'm inclined to agree that realistically the OP should just take one of the offers made to him.
In trading though this sort of thing (fat finger error or a salesperson/voice broker misquoting something or not paying attention and giving an overly generous quote just after the price of something has rallied) would be reliant on the goodwill of the counterparty to undo, otherwise if the trade has been done then they're obliged to settle. You can't necessarily phone back a day later after your counterparty has done whatever/has whatever position and then necessarily expect a trade to be undone as some of their subsequent trades are in part contingent on the fact that that trade happened.
So hypothetically: "There is no scenario that I can see that the OP would be reasonably due any other form of compensation" suppose the OP was a small system builder or reseller and this component was for a customer who had since been quoted a price and already paid the OP, OP priced things competitively but wouldn't have done so quite as competitively if he'd had to pay £100 or £200 more for this component. There is a hypothetical scenario where the OP acting in good faith, gets a competitive price, puts on his usual mark up and then gets left out of pocket.