Jeepers creepers! That sounds like an ordeal and a half! To be fair I've always been pretty outspoken about Zavvis terrible practices. I remember when they first started a couple of years ago now, their trust pilot score was abysmal and I heard no end to people's horror stories.
People never got their orders delivered nor sent out for that matter, much like you they battled them for a refund for 6+ months and again like yourself only received refunds once threatening legal action.
I still chuckle when ever someone pops up advocating for Zavvi on my comments about their scamming behaviour.
Way I see it is, there's the odd few who received their orders for small items below $25 so they think that Zavvi is trustworthy.
Like I always say to them, wait till you order a $4-500 figure and never see it arrive. I guarantee you'll change your tune mighty fast.
They make it near impossible to get direct customer service because they bet on the people who will just give up after getting the run around for a few weeks (as strange as it sounds I've met more than a few people that have). I for one would fight them tooth and nail for my refunds but I've never been fact enough to place an order for a $5 item let alone buy a figure. In short Zavvi stated off as a scam and seems like they still make their rounds on unsuspecting customers till this day.
Glad to hear you've got your money back though. Hope you don't ever have to deal with them again