How to decline gifts from people

So I've got someone in my family who was so lovely and lent me some money as I'm struggling atm.but now they've offered to get my little ones first school bag and some shoes, but it's making me super uncomfortable. I hate accepting money off people and although I really needed the help I felt humiliated at the same time. I was planning on getting my daughter her first back pack and shoes when I next got paid, and tbh I want to do that myself as its her first year at primary school. Not sure how to decline nicely? They can be quite insistent so I know a 'oh thank you but no thanks' won't be enough and they'll think I'm just saying it to be polite 🤣 how can I decline the offer??