Car seat question

So I know I’m probably going to sound stupid, but my cousin bought me a car seat through my target registry about 14 weeks ago & my dumbass threw the box and receipt away not even thinking about it.. well tonight I was looking at it and noticed the chest clip is messed up and won’t stay latched. Is there any way I can take it back to the store and explain to them and show them what is wrong with it and them send me a replacement part or because I don’t have the receipt will and it’s been past 90 days will they not do anything about it? I don’t really know how all this works but I’m worried because I feel like it’s a safety hazard to my daughter