I live in a shared student accommodation and the WiFi doesnt reach my room very well and so I bought the Tp link TL-WA850RE which made the WiFi useable most of the time. After getting the extender, the whole internet system would drop out, no WiFi or ethernet on any device, and would have to reset the router. After a month or so of the WiFi cutting out and ringing Vodafone we figured out it was the extender. Now the WiFi in my room only often cuts out due to the poor coverage and Vodafone wont do anything about it. My question is, can anything be done to fix the extender such that it doenst brick the system? Is this a known fault? Could I get a refund? 

Any suggestions or advice is greatly appreciated. 

Thanks