Worst thing I've ever bought is an Ivor Dewdney's 'Cornish pasty' from Newton Abbot. One bite and and the whole thing went straight in the nearest bin. Which promptly regurgitated it onto the pavement.
The last time we were in St. Ives, I wanted a 'proper' Cornish pasty, so obviously chose the shop that had a huge queue outside.
Two bites in, and it went into the bin. I would genuinely have preferred a Tesco 'value' pasty to the tasteless, gristly lump of mush ensconced in slimy 'pastry' that I received. I was tempted to take it back and complain but the queue was still huge and the shop was still packed out.
Other than that I also have a Dyson regret but its not any of their upright vacuums - I have a DC14 and a DC27 and both are brilliant.
Mine is the wodnerful HD-01 Supersonic hairdryer that I bought for Mrs. B a few years ago. She said it was actually very good but it then started cutting out as she moved it around her head. I'm sure its only the mains lead terminations inside that have come adrift (their vacuums suffer from this as well) but Dyson no longer support it, will not release any service information for it and no Dyson specialists will touch them due to the above issues.
Never mind, I bet someone on t'internet has taken one apart. Er...yes, thay have, and you have to snap the two control buttons off the switches in order to remove the handle. What an utterly genius piece of production engineering and design for serviceability.
Mrs B. replaced it long ago with a Lidl £19 special (Made in Germany, solid as you like and held together with screws that can be undone!). I'm still determined to fix it but it'll be off to eBay once I have done. Dyson has also lost me as a customer and I had an enjoyable few months taking the piss out of every "we're technology leaders" post they made on LinkedIn in 2022, but I've moved on now.