I went on a site called Bravissimo (bra site based in the UK) and bought a sports bra. Then I found out when money was taken out of my bank account that I had bought 3 of the same bra. Well I just hope that they fit me!
If you challenge the payment, keep a record of any correspondence you have with them and contact your bank if you are not satisfied with the outcome.
Yes, some online retailers are very scammy and will send and charge for multiple items when you have only purchased one. If bravissimo have a record of doing this, your bank will likely know about it and give you a refund, no questions asked.
This happened to my wife a couple of years ago, she ordered something online and they sent several items through and started adding ongoing fees and stuff. I made sure she challenged it properly with her bank and she got 100% back as well as being able to keep the items.
Also never pay for anything online using those "secure payment methods" where you have to log into your online banking account. This is a red flag that it's scammy, because once you do that then it becomes much more difficult to claim a refund. Normally you can claim a refund and it is the responsibility of the retailer to prove that everything is above board, but if you've used a secure payment method like I mentioned above, it's up to YOU to prove that you got scammed.
Many people actually think the opposite, that a secure payment method protects them. Unless your bank is a dodgy 3rd world bank that doesn't give refunds for credit card fraud, it's the opposite: a standard credit card payment where you just enter your card details is by far the safest way to pay for something online.