I purchased 4 F & F Signature Womens Nightwear today from Tesco's Castle Lane Bournemouth. The Total was £38.00 however, it registered a Muti-buy saving of £34.00, the saving stated Mango 2 for £2.00. Therefore, each item of very nice Nightwear cam to just a £1 each, the items purchased varried from £6 tp £12.
I suggest you use the self check out tills and get the operator to remove the tags for you!
They may well have discovered the glitch by now, but it did work at 11am today!
Couldn't test on line as had to register with Tesco Clothing!