Dress doesn’t fit - shop ordered wrong size

Hi,

im posting to find help for a family friend, she ordered a dress from a local bridal shop in November last year and it arrived in late march/early april. The store owner measured her and stated she needed a size 28 dress. The bride to be is a size 14 bottom and size 16-18 top usually and phoned the owner the day after she was measured to share her concerns about ordering a size 28. The dress is from America so it is my understanding that usually this means a size or two bigger is necessary but surely not 5 sizes.
Upon the first fitting the dress was way too big, the top is a corset style and was huge and loose, the waist was also too big. The dress is designed with pads inside so a bra is not necessary, because it’s way too big these pads are now almost under the arms when wearing the dress.
The owner took the dress and gave it to a dressmaker. The dressmaker came to the brides house to measure her in the dress and then made alterations. 4 inches was taken in on the waist and the corset was originally a 54-56” bust and had to be taken in to 44-46” to fit the bride.
The second fitting arrived and upon trying the dress the style has completely changed and the corset does not sit right as the dressmaker has taken it in way to much. The dress is basically ruined and looks nothing like it should.
The owner is denying any responsibility and refusing a refund. The dressmaker still has the dress in her possession and the store owner is refusing to receive it back from her, trying to force the bride to accept it.
Said owner has also shouted profanities at the bride and my mum and been extremely rude. The dress company have told the bride that the owner should never have ordered a 28 and cannot understand why she did. They also states that the dresses cannot be taken in as much as they have been in this case.
Also the dressmaker told the bride that the dress shouldn’t have been altered so much and that the size was wrong, she also told the store owner this but the store owner is completely denying being told this.
The wedding is on the 9th June and as you can imagine she is extremely upset this, especially since she has paid off the full amount of the dress already.

I was wondering if anyone could point me in the right direction in terms of the law. Is the bride able to write a letter to cancel the contract for the dress as she has not received it yet and I’ve read that you have upto 14 days after receiving the item to cancel it and obtain a refund.
Any help is much appreciated, thanks.