Baby city refusing to return faulty c****at

I've returned my safeway atlas due to irregular movement on the headrest. They are refusing to return it, the rep stated that there is no fault with the seat. I will never put my child in that seat. This is so inconvenient being on maternity leave and I have to drive up and down where my husband was supposed to make one of the drop off trips for my son. I purchased the seat in December and they have returned it for other customers. I have a joie Seat for over 2 years without any issues. This is not going to end very well.