Mixed up the order

Hi I would like to complain about Bash online...I placed an order on the 26th of February 2024 and I have all the confirmation of details and payment made to them but they captured my details incorrectly they mixed it with someone else's order even allowed someone else to call and make changes to my order after I called them to find out and confirmed if they had the correct details for me. They told me there's someone called Tebogo who called them to make changes to my order I don't know how and why they allow that...do they not follow data protection act and GDPR? I'm extremely not happy with what they did and the fact that my order is now delayed further can action be taken against them please I need my order or they will just have to refund me my money and I'd like some compensation for the inconvenience caused