So I bought my gen 4 ipad retina from apple as a refurbished product back in 2013. Battery has not been keeping charge recently so rang apple to find out how much a fix was. They quoted £276 for a full hardware fix!!!
But then the nice man said you might be eligible for a consumer law replacement if you get the hardware fault diagnosed at an apple store (free) or authorised service centre (charge which is refundable). He gave me a case number, i took it into a centre, paid £36 and three days later I got a shiny new like for like replacement. Even better, I'll get the £36 back.
Worst case scenario you've only lost £36 if there is no fault and you haven't tried the usual DFU restore processes.