REFUND

I bought 3 dashcams and returned them, first one was freezing, second one was wrong description, and on these 2 i was opting for my account to be credited On the 3rd camera, the rear interior was only working when i remove the charger cable then i retuned and asked for a refund, that's where the problem started, I'm being told that they cant refund my money cause i didn't return the memory cad but its the first thing i put in the box, took it to their office, the guy checked, sealed and took a picture Infront of me ,now I'm told i need to replace the missing item