Rigby and peller just fit the bra to your back size, they dont measure, as you can put on one bra and it may come up slightly bigger or smaler than the next, just ike clothes do.
If you have bulge at the side and arent particularly overweight then that has to do with the depth of the bra at the sides, eg, the style of it.
If you have a full bust, ie an F cup as you said soya, and you also have a small band measurement, then the particular bra you were fitted with may not be exactley right, it may be the best they had for you, and it may take a little while to get used to it.
Saying that, justbecause soemthing fits you, like with other clothes doesnt mean it 'feels' uncomfy.
I dont know what makes bravissimo sell. I now go to debenhams to get my bras, and because I used to work in R + p, I know the makes they preferred to put women in, and the shapes. R + P sell all types of brands.
These are my faves, and I am a 34E, which is the equivelantto a 32F.
Fantasie, they have really good support, and excellent strap width, which id really importnat for keep ing larger cups supported. Fantasie were made by the same company that makes the off the pge R + P bras.
Freya, they have some wonderful bras, and particularly flattering are the balconette styles.
Some actual Debenhams ones are good, a few of their t shirt bras Are nice.
Prima Donna-- prob THE best bras for comfort, fit and shape. And they have some beautiful colours and designs.
Marie Jo, to for slightly smaller cups.
Dont buy bras which are to stretchy round the back, as they give too easily, and over time.