I was shocked to see so many negative reviews of Missguided. I live in the US and I've purchased large orders from Missguided several times and I've never had any issues. I only purchase from them when they are having a 40-50% promotion and I always do big-ish orders during these promotions so I never have to pay for shipping.
I always shop online and Missguided is one of the sites that I am frequently looking through and purchasing from. I've read some of the negative reviews and I highly suggest to not let that deter you from shopping on this site. The prices are great (especially during the big promotions) and the quality is good for what you pay for.
If you ever have any issue with your order the best thing to do, in my opinion, is to reach out to them on their social media accounts (Instagram, Facebook, Twitter). They're always very responsive on there.