Bought a refurbished iPhone 6s. Looked great but b...

Bought a refurbished iPhone 6s. Looked great but battery had 42% wear making it 'very bad' according to Battery Doctor app. Returned it OK and and was told refund would be issued in 3-5 working days. Contacted them again on day 6 and only this prompted them to issue refund for which I now have to wait another week. If they hadn't returned the SIM card I left in the phone it would have been one star.